Method for detecting body parameters

ABSTRACT

A method for detecting biometric parameters includes the steps of performing a bone graft procedure on at least one vertebra of a spine, providing at least one biometric sensor at the at least one vertebra, the sensor measuring at least one parameter selected from the group consisting of pressure, tension, shear, relative position, and vascular flow in an adjacent surrounding, and measuring the at least one biometric parameter at the vertebra with the sensor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is:

-   -   a continuation-in-part of U.S. patent application Ser. No.        11/391,988, filed on Mar. 29, 2006 (which application claims the        priority of U.S. Provisional Patent Application No. 60/665,797,        filed Mar. 29, 2005, and U.S. Provisional. Patent Application        Nos. 60/763,761 and 60/763,869, both filed Feb. 1, 2006);    -   a continuation-in-part of U.S. patent application Ser. No.        13/014,767, filed on Jan. 27, 2011;    -   a continuation-in-part of U.S. patent application Ser. No.        13/014,773, filed on Jan. 27, 2011;    -   a continuation-in-part of U.S. patent application Ser. No.        13/014,782, filed on Jan. 27, 2011;    -   a continuation-in-part of U.S. patent application Ser. No.        13/015,685, filed on Jan. 28, 2011;    -   a continuation-in-part of U.S. patent application Ser. No.        12/604,072, filed on Oct. 22, 2009 (which application claims the        priority of U.S. Provisional Patent Application No. 61/196,914,        filed Oct. 22, 2008);    -   a continuation-in-part of U.S. patent application Ser. No.        12/604,083, filed on Oct. 22, 2009 (which application claims the        priority of U.S. Provisional Patent Application No. 61/196,915,        filed Oct. 22, 2008);    -   a continuation-in-part of U.S. patent application Ser. No.        12/604,099, filed on Oct. 22, 2009 (which application claims the        priority of U.S. Provisional Patent Application No. 61/196,916,        filed Oct. 22, 2008);    -   a continuation-in-part of U.S. patent application Ser. No.        12/748,099, filed on Mar. 26, 2010 (which application claims the        priority of U.S. Provisional Patent Application No. 61/211,023,        filed Mar. 26, 2009);    -   a continuation-in-part of U.S. patent application Ser. No.        12/748,112, filed on Mar. 26, 2010 (which application claims the        priority of U.S. Provisional Patent Application No. 61/211,023,        filed Mar. 26, 2009);    -   a continuation-in-part of U.S. patent application Ser. No.        12/748,126, filed on Mar. 26, 2010 (which application claims the        priority of U.S. Provisional Patent Application No. 61/211,023,        filed Mar. 26, 2009);    -   a continuation-in-part of U.S. patent application Ser. No.        12/748,136, filed on Mar. 26, 2010 (which application claims the        priority of U.S. Provisional Patent Application No. 61/211,023,        filed Mar. 26, 2009);    -   a continuation-in-part of U.S. patent application Ser. No.        12/748,147, filed on Mar. 26, 2010 (which application claims the        priority of U.S. Provisional Patent Application No. 61/211,023,        filed Mar. 26, 2009),        the entire disclosures of which are hereby incorporated herein        by reference in their entireties.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

n/a

FIELD OF THE INVENTION

The present invention lies in the field of medical devices, inparticular, in the field of externally applied and embedded sensorsystems for detecting specific parameters of a physiological (e.g.,musculoskeletal) system and determining the exact anatomic site ofactivity, and methods for detecting parameters of anatomical sites.

BACKGROUND OF THE INVENTION

Sensor technology has been disclosed in U.S. Pat. Nos. 6,621,278,6,856,141, 6,984,993, 7,080,554, 7,266,989, 7,313,491, 7,325,460,7,520,179, 7,533,571, 7,710,124, and 7,716,988 and assigned to NexenseLtd. (the “Nexense patents”). The entire disclosures of which are herebyincorporated herein by reference in their entireties.

It would be beneficial to apply existing, sensor technology to biometricdata sensing applications so that health care personnel can determinecharacteristics of anatomic sites.

BRIEF SUMMARY OF THE INVENTION

It is accordingly an object of the present invention to provide a sensorsystem that can detect specific parameters (e.g., of a musculoskeletalsystem) and determine the exact anatomic site of activity and methodsfor detecting parameters of anatomical sites that overcome thehereinafore-mentioned disadvantages of the heretofore-known devices andmethods of this general type and that provides an externally appliedand/or embedded sensor to give healthcare providers real timeinformation regarding their patients. The information can includepathological processes as well as information regarding surgicalprocedures and implanted devices. The sensors can be activated byinternal or external mechanisms, and the information relayed throughwireless pathways. The sensor system will allow early intervention ormodification of an implant system and can use existing sensors. Forexample, the sensors disclosed in Nexense patents can be used.

With the foregoing and other objects in view, there is provided, inaccordance with the invention, a method for detecting biometricparameters including the steps of performing a surgical procedure on atleast one bone, implanting at least one biometric transceiver at the atleast one bone, transmitting a first energy wave from the transceiverinto a procedure area including at least one of the bone and an areaadjacent the bone, quantitatively assessing the behavior of the energywave with the transceiver, after transmitting the first energy wave:transmitting a second energy wave from the transceiver into theprocedure area; and quantitatively assessing the behavior of the secondenergy wave. At least one of the first and second energy waves arepulsed during transmission in a vibratory manner to stimulate theprocedure area in accordance with at least one detected parameter of theprocedure area. A current status is determined of the at least oneparameter of the procedure area selected from the group consisting ofpressure, tension, shear, relative position, bone density, fluidviscosity, temperature, strain, angular deformity, vibration, venousflow, lymphatic flow, load, torque, distance, tilt, shape, elasticity,motion, bearing wear, subsidence, bone integration, change in viscosity,particulate matter, kinematics, stability, and vascular flow with thetransceiver based upon a comparison between the assessed behavior of thefirst and second energy waves.

In accordance with another mode of the invention, there are provided thesteps of transmitting data relating to the at least one biometricparameter to an external source and analyzing the data to evaluate abiometric condition of the at least one bone.

In accordance with a further mode of the invention, a set of thetransceivers is provided on the at least one bone.

In accordance with an added mode of the invention, based upon theevaluation of the biometric condition of the at least one bone, acurrently ongoing interoperative procedure at the procedure area ischanged.

In accordance with an additional mode of the invention, based upon theevaluation of the biometric condition of the at least one hone, theanatomic condition relating to the procedure area is chronicallymonitored.

In accordance with yet another mode of the invention, energy is providedfrom outside the procedure area to the transceiver to power thetransceiver and, thereby, create the energy wave and quantitativelyassess the behavior of the energy wave.

In accordance with yet a further mode of the invention, the energy isprovided through at least one of an electromagnetic couple, a magneticcouple, a capacitive couple, an inductive couple, a sonic couple, anultrasonic couple, a fiber optic couple, an optical couple, and aninfrared couple.

In accordance with yet an added mode of the invention, a set of thebiometric transceivers is provided at the procedure area, an energy waveis transmitted from the transceivers into the procedure area, thebehavior of the energy wave is quantitatively assessed with at least oneof the transceivers, and, based upon the assessed behavior, a currentstatus of the at least one parameter is determined.

In accordance with yet an additional mode of the invention, a set of thebiometric transceivers is provided at the procedure area, energy wavesare transmitted from the transceivers into the procedure area, thebehaviors of the energy waves are quantitatively assessed with thetransceivers, and, based upon the assessed behaviors, a current statusof the at least one parameter is determined.

In accordance with again another mode of the invention, the areaadjacent the bone is a second bone different from the bone, and anenergy wave is transmitted from the transceiver, into the second bone,and back to the transceiver.

In accordance with again a further mode of the invention, the statusdetermining step is carried out by determining a current status of atleast two of the group of parameters with the transceiver.

In accordance with a concomitant mode of the invention, the at least onebiometric transceiver is embedded at the at least one bone.

Other features that are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a sensor system that can detect specific body parameters anddetermine exact anatomic site of activity and methods for detection, itis, nevertheless, not intended to be limited to the details shownbecause various modifications and structural changes may be made thereinwithout departing from the spirit of the invention and within the scopeand range of equivalents of the claims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof, will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of embodiments the present invention will be apparent fromthe following detailed description of the preferred embodiments thereof,which description should be considered in conjunction with theaccompanying drawings in which:

FIG. 1 is a diagrammatic, fragmentary, lateral view of a portion of aspine with a non-instrumented fusion of the spine and sensors accordingto the invention;

FIG. 2 is a diagrammatic, fragmentary, anterior-posterior view of thespine portion of FIG. 1;

FIG. 3 is a diagrammatic, fragmentary, lateral view of a portion of aspine with an intervertebral cage and sensors according to theinvention;

FIG. 4 is a diagrammatic, fragmentary, anterior-posterior view of thespine portion of FIG. 1 with sensors according to the invention inpedical screws

FIG. 5 is a diagrammatic, fragmentary, lateral view of a portion of aspine with an intervertebral disc implant and sensors according to theinvention;

FIG. 6 is an illustration of an exemplary embodiment of spinal columnand sensor arrays according to the invention;

FIG. 7 is an illustration of an exemplary embodiment of spinal columnand sensor arrays providing positional information according to theinvention;

FIG. 8 is an illustration of an exemplary embodiment of vertebrae havingsensor arrays according to the invention;

FIG. 9 is an illustration of an exemplary embodiment of a spinal implantand cage according to the invention;

FIG. 10 is a diagrammatic, fragmentary, enlarged cross-sectional view ofa sensor inserting instrument according to the invention;

FIG. 11 is a diagrammatic, fragmentary cross-sectional view of an upperfemur with sensors according to the invention implanted with theinstrument of FIG. 10;

FIG. 12 is a diagrammatic, fragmentary cross-sectional view of avertebra with sensors according to the invention implanted with theinstrument of FIG. 10;

FIG. 13 is a diagrammatic, fragmentary cross-sectional view of a femurwith sensors in a screw according to the invention;

FIG. 14 is a diagrammatic, fragmentary cross-sectional view of a femurwith implanted sensors according to the invention;

FIG. 15 is a diagrammatic, fragmentary cross-sectional view of avertebra with sensors according to the invention;

FIG. 16 is a diagrammatic, fragmentary perspective view of an exemplaryembodiment of a system for preventing infection on an implanted deviceaccording to the invention;

FIG. 17 is a diagrammatic, fragmentary perspective view of an exemplaryembodiment of an implanted device having bacteria in synovial fluidaround an artificial joint according to the invention;

FIG. 18 is a diagrammatic, fragmentary perspective view of an exemplaryembodiment of a pulsed electric field emitted in proximity to animplanted device according to the invention;

FIG. 19 is a diagrammatic illustration of bacterial response to a fieldin proximity to an exemplary embodiment of an implanted device accordingto the invention;

FIG. 20 is a diagrammatic, fragmentary perspective lateral view of anexemplary embodiment of a post-operative pain inhibitor system forpost-operative pain treatment of a skeletal system of a leg according tothe invention;

FIG. 21 is a diagrammatic, fragmentary perspective anteroposterior viewof the post-operative pain inhibitor system for post-operative paintreatment of a skeletal system of a leg according to the invention;

FIG. 22 is a diagrammatic, fragmentary perspective anteroposterior viewof an exemplary embodiment of a post-operative pain inhibitor system forpost-operative pain treatment of a skeletal system of a leg according tothe invention;

FIG. 23 is a diagrammatic, fragmentary perspective lateral view of thepost-operative pain inhibitor system for post-operative pain treatmentof a skeletal system of a leg according to the invention;

FIG. 24 is a diagrammatic, fragmentary perspective anteroposterior viewof an exemplary embodiment of a post-operative pain inhibitor system forpost-operative pain treatment of the skeletal system according to theinvention;

FIG. 25 is a diagrammatic, fragmentary perspective lateral view of anexemplary embodiment of a post-operative pain inhibitor system forpost-operative pain treatment of the skeletal system according to theinvention;

FIG. 26a is an anteroposterior view of an exemplary embodiment of aprosthetic component having integrated electrical leads to provide asignal to a peripheral nerve fiber to reduce post-operative painaccording to the invention;

FIG. 26b is a lateral view of the prosthetic component of FIG. 26 a;

FIG. 27 is a diagrammatic, fragmentary perspective anteroposterior viewof an exemplary embodiment of components of the post-operative paininhibitor system integrated into more than one prosthetic componentsaccording to the invention;

FIG. 28 is a diagrammatic, fragmentary perspective lateral view of anexemplary embodiment of components of the post-operative pain inhibitorsystem integrated into more than one prosthetic components according tothe invention;

FIG. 29 is a diagrammatic, fragmentary perspective anteroposterior viewof an exemplary embodiment of a hip prosthesis according to theinvention;

FIG. 30a is a diagrammatic, fragmentary, side elevationalanteroposterior view of an exemplary embodiment of a tibial implantaccording to the invention:

FIG. 30b is a diagrammatic, fragmentary, side elevational lateral viewof the tibial implant of FIG. 30 a:

FIG. 31a a diagrammatic, fragmentary, lateral view of an exemplaryembodiment of a cup implant according to the invention;

FIG. 31b a diagrammatic, fragmentary, anteroposterior view of anexemplary embodiment of a femoral implant according to the invention;

FIG. 32 is a diagrammatic, fragmentary, anterior-posterior,cross-sectional view of a knee joint with sensors according to theinvention;

FIG. 33 is a diagrammatic, fragmentary lateral, cross-sectional view ofa knee joint with sensors according to the invention;

FIG. 34 is a diagrammatic, front elevational view of leg bones inextension and a mechanical axis of the leg according to the invention;

FIG. 35 is a diagrammatic, fragmentary front elevational view of anexemplary embodiment of a plurality of sensors placed on a lower legaccording to the invention;

FIG. 36 is a diagrammatic, fragmentary lateral view of the plurality ofsensors placed on the lower leg of FIG. 35;

FIG. 37a is a diagrammatic, fragmentary lateral view of a lower leg withan exemplary embodiment of a plurality of sensor arrays in extensionaccording to the invention;

FIG. 37b is a diagrammatic, fragmentary lateral view of the lower leg ofFIG. 37a in flexion;

FIG. 38 is a diagrammatic, fragmentary lateral view of an exemplaryembodiment of the plurality of sensor arrays in communication with aprocessing unit and a screen for providing information according to theinvention;

FIG. 39 is a diagrammatic, fragmentary lateral view of a knee and anexemplary embodiment of joint implant and a sensor system according tothe invention;

FIG. 40 is a diagrammatic, fragmentary anteroposterior view of a kneeand an exemplary embodiment of a joint implant and a sensor system withsensor arrays according to the invention;

FIG. 41 is a diagrammatic, fragmentary, cross-sectional view of a hipjoint with sensors according to the invention;

FIG. 42 is a diagrammatic, fragmentary, lateral cross-sectional view ofvertebrae with sensors according to the invention;

FIG. 43 is a diagrammatic, fragmentary, axial cross-sectional view of avertebra with sensors according to the invention;

FIG. 44 is a diagrammatic, fragmentary cross-sectional view of a kneejoint with ultrasound active sensors according to the invention;

FIG. 45 is a diagrammatic illustration of an ultrasound transmitter anda computer screen showing a knee joint with ultrasound active sensorsaccording to the invention being treated;

FIG. 46 is a diagrammatic, enlarged, partially cross-sectional view of ahandle connected to an implantable sensor body according to theinvention;

FIG. 47 is a diagrammatic, enlarged, partially cross-sectional view ofthe handle of FIG. 46 disconnected from the sensor body;

FIG. 48 is a diagrammatic illustration of an exemplary embodiment of aninfra-red visualization system according to the invention;

FIG. 49 is a diagrammatic illustration of an exemplary embodiment of anelectromagnetic visualization system according to the invention;

FIG. 50 is a fragmentary, partially hidden, anterior view of a kneejoint with an exemplary embodiment of sensors according to theinvention;

FIG. 51 is a fragmentary, lateral view of the knee joint with anexemplary embodiment of sensors according to the invention;

FIG. 52 is a diagrammatic, fragmentary side elevational view of aligament;

FIG. 53 is a diagrammatic fragmentary side elevational view of theligament of FIG. 52 with a ligament sensor clamp according to theinvention in an adjacent position;

FIG. 54 is a diagrammatic, fragmentary side elevational view of theligament and ligament sensor clamp of FIG. 53 with the ligament sensorpartially attached;

FIG. 55 is a diagrammatic, fragmentary side elevational view of theligament and ligament sensor claim of FIG. 53 with the ligament sensorattached to the ligament;

FIG. 56 is a top plan view of an exemplary embodiment of a dynamicdistractor according to the invention;

FIG. 57 is a perspective view of the dynamic distractor of FIG. 56 in aminimum height state;

FIG. 58 is a perspective view of the dynamic distractor of FIG. 56opened for distracting two surfaces of the muscular-skeletal system;

FIG. 59 is a fragmentary anterior view of an exemplary embodiment of adynamic distractor placed in a knee joint according to the invention;

FIG. 60 is a fragmentary lateral view of the dynamic distractor of FIG.59 in a knee joint positioned in flexion;

FIG. 61 is a fragmentary lateral view of the dynamic distractor of FIG.59 in a knee joint coupled to an exemplary embodiment of a cutting blockaccording to the invention;

FIG. 62 is a fragmentary anterior view of the cutting block coupled tothe dynamic distractor of FIG. 61;

FIG. 63 is a perspective view of an exemplary embodiment of a dynamicdistractor including alignment measures according to the invention;

FIG. 64 is a fragmentary side elevational view of a leg in extensionwith an exemplary embodiment of a dynamic distractor in the knee jointregion according to the invention;

FIG. 65 is a fragmentary, front elevational view of the leg in extensionwith the dynamic distractor of FIG. 64;

FIG. 66 is a perspective view of an exemplary embodiment of a system andkit for measuring one or more parameters of a biological life formaccording to the invention;

FIG. 67 is a fragmentary, cross-sectional view of a portion of anultrasonic cannula system according to the invention;

FIG. 68 is a fragmentary, cross-sectional view of a portion of a singlesensor cannula deployment device according to the invention;

FIG. 69 is a fragmentary, cross-sectional view of a portion of a cannuladeployment device with multiple sensors;

FIG. 70 is a fragmentary, cross-sectional view of a portion of amulti-sensor cannula deployment device according to the invention;

FIG. 71 is a fragmentary side elevational view of an open knee surgerywith exclusion of soft tissue and cartilage and bone cuts with sensorsaccording to the invention deployed;

FIG. 72 is a fragmentary, cross-sectional view of a trocar tip accordingto the invention housing sensor elements;

FIG. 73 is fragmentary, cross-sectional view of an inserter for an arrayof sensors;

FIG. 74 is diagrammatic, side elevational view of a cutter housing anarray of sensors according to the invention;

FIG. 75 is a diagrammatic, side elevational view of a bone reamer;

FIG. 76 is a fragmentary, cross-sectional view of a sensor systemaccording to the invention implanted in a hip;

FIG. 77 is a fragmentary, cross-sectional view of a sensor systemaccording to the invention implanted in a femur;

FIG. 78 is a fragmentary, cross-sectional view of a cup sensor inserteraccording to the invention for deployment of multiple sensors;

FIG. 79 is a fragmentary, perspective view of an exemplary embodiment ofa system having sensor arrays according to the invention;

FIG. 80 is a diagrammatic, fragmentary perspective view of a hip implanthaving sensors according to the invention;

FIG. 81 is a diagrammatic, fragmentary perspective view of a hip implanthaving load sensors according to the invention;

FIG. 82 is diagrammatic, fragmentary perspective view of moving the hipimplant to measure load and position through a range of motion accordingto the invention;

FIG. 83 is a fragmentary, cross-sectional lateral view of two spinalsegments with a sensor implantion system according to the invention;

FIG. 84 is a fragmentary, axially cross-sectional view a vertebral levelwith a sensor implanted through a pedicle;

FIG. 85 is a block circuit diagram of an exemplary embodiment of amachine in the form of a computer system according to the invention;

FIG. 86 is a diagram of an exemplary embodiment of a communicationnetwork for measurement and reporting according to the invention;

FIG. 87 is a fragmentary front elevational view of an exemplaryembodiment of a medial knee implant according to the invention inflexion;

FIG. 88 is a fragmentary side elevational view of the medial kneeimplant of FIG. 87;

FIG. 89 is a fragmentary front elevational view of the medial kneeimplant of FIG. 87 in extension;

FIG. 90 is a fragmentary top plan view of the medial knee implant ofFIG. 87 in extension;

FIG. 91 is a fragmentary superior elevational view of an exemplaryembodiment of a trial plastic insert according to the invention;

FIG. 92 is a fragmentary side elevational view of the trial plasticinsert of FIG. 91;

FIG. 93 is a diagram of an exemplary embodiment of a wirelesscommunications system according to the invention;

FIG. 94 is a fragmentary side elevational view of a knee as it is takenthrough a range of motion;

FIG. 95 is a fragmentary elevational view of an exemplary embodiment ofa trial plastic insert with embedded sensors according to the invention;

FIG. 96 is a fragmentary side elevational view of an exemplaryembodiment of a smart instrument burring cartilage and bone off a femuraccording to the invention;

FIG. 97 is a fragmentary front elevational view of an exemplaryembodiment of a medial knee implant according to the invention inflexion;

FIG. 98 is a fragmentary side elevational view of the medial kneeimplant of FIG. 97;

FIG. 99 is an elevational view of an exemplary embodiment of a tibialinsert with the embedded sensors; and

FIG. 100 is an elevational view of the tibial insert of FIG. 99;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Aspects of the invention are disclosed in the following description andrelated drawings directed to specific embodiments of the invention.Alternate embodiments may be devised without departing from the spiritor the scope of the invention. Additionally, well-known elements ofexemplary embodiments of the invention will not be described in detailor will be omitted so as not to obscure the relevant details of theinvention.

Before the present invention is disclosed and described, it is to beunderstood that the terminology used herein is for the purpose ofdescribing particular embodiments only and is not intended to belimiting. It must be noted that, as used in the specification and theappended claims, the singular forms “a,” “an,” and “the” include pluralreferences unless the context clearly dictates otherwise.

While the specification concludes with claims defining the features ofthe invention that are regarded as novel, it is believed that theinvention will be better understood from a consideration of thefollowing description in conjunction with the drawing figures, in whichlike reference numerals are carried forward. It is noted that similarreference numerals and letters refer to similar items in the followingfigures, and thus once an item is defined in one figure, it may not bediscussed or further defined in the following figures. The figures ofthe drawings are not drawn to scale.

An externally applied sensor system according to the present inventioncan be used to evaluate skin integrity and pathological pressure thatcan lead to skin ischemia and ultimately skin breakdown (Decubiti). Itis important to detect certain parameters that can lead to skinbreakdown. Elements such as pressure, time, shear, and vascular flow,for example, are important to detect. The specific anatomic location isneeded.

The sensor system of the present invention can be embedded in a thin,adhesive, conforming material that is applied to specific areas ofconcern. Exemplary areas include the heel, hips, sacrum, and other areasof risk. These sensors map out the anatomic area. If thresholdparameters are exceeded, the sensors inform a telemetric receiver that,in turn, activates an alarm to the nurse or other health careprofessional. In one exemplary application, the information is used tocontrol the bed that the patient is lying upon to relieve the area ofconcern. In particular, adjustment of aircells in the mattress can bemade to unload the affected area of concern.

The external sensor system can be configured in various ways. In anexemplary embodiment, a sensor is disposed within a thin, conformableadhesive that is applied directly to the patient's body and is poweredby a thin lithium battery. This sensor(s) documents specific parameterssuch as pressure, time, shear, and vascular flow. The sensortelemetrically informs a receiving unit and sets an alarm if certainpre-programmed parameters are exceeded. In one embodiment where a visualaid is provided (such as a computer screen displaying the patient's bodyoutline, the exact area of concern can be highlighted and, thereby,visualized by the health care professional.

Embedded sensors are needed to detect certain internal parameters thatare not directly visible to the human eye. These sensors will be used inspecific locations to detect specific parameters.

One way of embedding a sensor is through an open surgical procedure.During such a surgical procedure, the sensor is embedded by the surgeondirectly into bone or soft tissue or is attached directly to a securedimplant (e.g., a prosthesis (hip, knee)). The sensor system is usedduring the surgical procedure to inform the surgeon on the positionand/or function of the implant and of soft tissue balance and/oralignment. The sensor is directly embedded with a penetrating instrumentthat releases the sensor at a predetermined depth. The sensor isattached to the secured implant with a specific locking system oradhesive. The sensor is activated prior to closure for validating thesensor.

Another way of embedding a sensor is through a percutaneous procedure.The ability to implant sensors in specific locations is important toevaluate internal systems. Sensors of varying diameters can be implantedinto bone, soft tissue, and/or implants. The procedure is applied undervisualization supplied, for example, by fluoroscopy, ultrasound imaging,and CAT scanning. Such a procedure can be performed under local orregional anesthesia. The parameters evaluated are as set forth herein.The percutaneous system includes a thin instrument with a sharp trocarthat penetrates the necessary tissue plains and a deployment armreleases the sensor(s) at a predetermined depth(s). The instrument couldalso house the necessary navigation system to determine the specificanatomic location required.

The parameters to be evaluated and time factors determine the energysource required for the embedded sensor. Short time frames (up to 5years) allow the use of a battery. Longer duration needs suggest use ofexternal activation or powering systems or the use of the patient'skinetic energy to supply energy to the sensor system. These activationsystems can be presently utilized. The sensors would also be activatedat predetermined times to monitor implant cycles, abnormal motion andimplant wear thresholds.

Information is received telemetrically. In one exemplary embodiment, thesensors are preprogrammed to “activate” and send required information ifa specific threshold is exceeded. The sensors could also be activatedand used to relay information to an external receiver. Furtherapplications allow readjustment of a “smart implant” to release specificmedications, biologics, or other substances, or to readjust alignment ormodularity of the implant.

The sensor system is initially activated and read in a doctor's officeand further activation can occur in the patient's house, with thepatient having ability to send the information through Internetapplications, for example, to the physician.

Software will be programmed to receive the information, process it, and,then, relay it to the healthcare provider.

The sensor system of the present invention has many differentapplications. For example, it can be used to treat osteoporosis.Osteoporosis is a pathological condition of bone that is characterizedby decreased bone mass and increased risk of fracture. It is wellaccepted that bone-mineral content and bone-mineral density areassociated with bone strength.

Bone density is an extremely important parameter of the musculoskeletalsystem to evaluate. Bone density measurements are used to quantify aperson's bone strength and ultimately predict the increased risksassociated with osteoporosis. Bone loss leads to fractures, spinalcompression, and implant loosening. Presently, physicians use externalmethods such as specialized X-rays.

The unit of measurement for bone densitometry is bone-mineral content,expressed in grams. Bone density changes are important in the evaluationof osteoporosis, bone healing, and implant loosening from stressshielding. Another important evaluation is in regard to osteolysis.Osteolysis can destroy bone in a silent manner. It is a pathologicalreaction of the host to bearing wear, such as polyethylene. Thepolyethylene particles activate an immune granulomatous response thatinitially affects the bone surrounding the implant. Bone density changeswill occur prior to cystic changes that lead to severe bone loss andimplant failure.

There are multiple external systems that can evaluate bone density. Theproblems with such systems encountered are related to the varioussystems themselves, but also to the socio-economic constraints ofgetting the patient into the office to evaluate a painless disease;coupled with the constricted payment allocations that cause longintervals between evaluations.

Sensors used according to the present invention allow evaluation ofchanges in bone density, enabling health care providers to know realtime internal data. Application of the sensors can assess osteoporosisand its progression and/or response to treatment. By evaluating changesin bone density, the sensors provide early information regardingfracture healing and early changes of osteolysis (bone changes relatingto polyethylene wear in implants).

Although the instrumentation various with different modalities, allrecord the attenuation of a beam of energy as it passes through bone andsoft tissue. Comparisons of results are necessarily limited to bones ofequal shape, which assumes a constant relationship between the thicknessof the bone and the area that is scanned. Moreover, the measurements arestrictly skeletal-site-specific; thus, individuals can be compared onlywhen identical locations in the skeleton are studied.

Dual-energy x-ray absorptiometry can be used to detect small changes inbone-mineral content at multiple anatomical sites. A major disadvantageof the technique is that it does not enable the examiner todifferentiate between cortical and trabecular bone. Quantitativeultrasound, in contrast to other bone-densitometry methods that measureonly bone-mineral content, can measure additional properties of bonesuch as mechanical integrity. Propagation of the ultrasound wave throughbone is affected by bone mass, bone architecture, and the directionalityof loading. Quantitative ultrasound measurements as measures forassessing the strength and stiffness of bone are based on the processingof the received ultrasound signals. The speed of sound and theultrasound wave propagates through the bone and the soft tissue.Prosthetic loosening or subsidence, and fracture of thefemur/tibia/acetabulum or the prosthesis, are associated with bone loss.Consequently, an accurate assessment of progressive quantifiable changesin periprosthetic bone-mineral content may help the treating surgeon todetermine when to intervene in order to preserve bone stock for revisionarthroplasty. This information helps in the development of implants forosteoporotic bone, and aids in the evaluation of medical treatment ofosteoporoses and the effects of different implant coatings.

The sensor system of the present invention can be used to evaluatefunction of internal implants. Present knowledge of actual implantfunction is poor, Physicians continue to use external methods, includingX-rays, bone scans, and patient evaluation. However, they are typicallyleft only with open surgical exploration for actual investigation offunction. Using sensors according to the present invention permitsdetection of an implant's early malfunction and impending catastrophicfailure. As such, early intervention is made possible. This, in turn,decreases a patient's morbidity, decreases future medical care cost, andincreases the patient's quality of life.

The sensors can be attached directly to implant surfaces(pre-operatively and/or intra-operatively) and/or directly to theimplant-bone interface. Sensors can be implanted into the bone and softtissue as well. In such an application, the physician could evaluateimportant parameters of the implant-host system. Exemplary parametersthat could be measured include: implant stability, implant motion,implant wear, implant cycle times, implant identification, implantpressure/load, implant integration, joint fluid analysis, articulatingsurfaces information, ligament function, and many more.

Application of sensors according to the invention allows one todetermine if the implant is unstable and/or if excessive motion orsubsidence occurs. In an exemplary application, the sensor can beconfigured to release an orthobiologic from an activated implantedmodule to increase integration. Alternatively and/or additionally, theimplant system with the sensors can be used to adjust theangle/offset/soft tissue tension to stabilize the implant if needed.

Sensors can be used to detect whether or not implant bearings arewearing out. Detectable bearing parameters include early wear, increasedfriction, etc. An early alarm warning from the sensor could enable earlybearing exchange prior to catastrophic failure.

A joint implant sensor can detect an increase in heat, acid, or otherphysical property. Such knowledge would provide the physician with anearly infection warning. In an exemplary infection treatmentapplication, the sensor can activate an embedded module that releases anantibiotic.

The sensors can be used to analyze knee surgeries. Such sensors can beplaced posteriorly in the knee to evaluate popliteal artery flow,pressure, and/or rhythm. A femoral implant sensor is placed anteriorlyto monitor femoral artery/venous flow, pressure, and/or rhythm. Aninternal vascular monitor can be part of the implant and include devicesto release antihypertensive or anti-arrhythmic modules to modifyvascular changes when needed.

In one exemplary embodiment, the internal orthopedic implant is, itself,the sensor of the present invention. In a trauma situation, for example,the reduction screw can be both the implant and the sensor. Such a screwcan detect abnormal motion at the fracture site and confirm increase indensity (i.e., healing). Such an application allows percutaneousimplantation of bone morphogenic protein (BMP) to aid in healing or apercutaneous adjustment of the hardware.

The sensor of the present invention can be used in spinal implants. Asensor placed in the spine/vertebrae can detect abnormal motion at afusion site. The sensor evaluates spinal implant integration at theadjacent vertebral segments and/or detects adjacent vertebral segmentinstability. Implanted sensors can activate a transitioning stabilizingsystem or implant and determine the areas of excessive motion to enablepercutaneous stability from hardware or an orthobiologic.

Referring now to the figures of the drawings in detail and first,particularly to FIG. 1 thereof, there is shown a fragmentary lateralview of a fusion of a portion of the spine. An upper vertebra 10 isseparated from a lower vertebra 20 by a disc 30. A bone graft 40 iscovered first by an inferior facet 50 and second by a superior facet 60.FIG. 2 is an anterior-posterior view of the spine portion of FIG. 1 inwhich the bone graft 40 is shown on either side of the disc 30 withopposing transverse processes 70. Sensors 1 according to the presentinvention can detect and transmit information regarding motion and loadsof the vertebra 10, 20 and are implanted in various spinal elements. Theelements can include the spinal pedicles 80, transverse processes 70,facets, etc.

FIGS. 1 and 2 depict how sensors 1 of the present invention can be usedin non-instrumented fusions of the spine. The sensors 1 are activated atvariable times in the post-operative period. Abnormal or excessivemotion around the fusion “mass” helps detect a non-union, for example.

FIG. 3 depicts how sensors 1 of the present invention can be use ininstrumented spinal fusions. More particularly, the sensors 1 areincorporated into the “cage” instrumentation 130 in between an inferiorvertebral plate 110 and a superior vertebral plate 120. Such a sensor 1detects motion and load and is activated to transmit information in thepost-operative period to help determine if the fusion mass was solid.

FIG. 4 depicts how sensors 1 of the present invention can be used inpedicle screws 130. More particularly, sensors 1 are incorporated intothe pedicle screw 130 to help detect any abnormal motion betweenvertebrae in the fusion mass.

FIG. 5 depicts how sensors 1 of the present invention can be use ininvertebral disc implants (replacements). More particularly, anartificial disc replacement 140 has sensors 1 placed on the metal-boneinterface, for example. These sensors 1 detect loads as well as motionto help, intra-operatively, in the placement of the disc 140 and,post-operatively, determine stable integration of the disc-boneinterface. Internal sensors to detect “normal” motion between thearticulating disc and external interfaces help confirm,post-operatively, that the disc replacement is optimally functioningwith variable loads and spinal motion.

FIG. 6 is an illustration of a spinal column and sensors in accordancewith an exemplary embodiment of the invention. The human spine comprisescervical, thoracic, and lumbar regions respectively corresponding toC1-C7, T1-T12, and L1-L5. A healthy spinal column has a mechanical axisin an upright position that distributes loading that minimizes stress oneach vertebrae. An example of a spinal deformity that can requirecorrection is scoliosis, which is a curving of the spine. In general,spinal deformities can often be corrected using devices that place thespine or help the spine be in the most ideal mechanical situation. Inany spinal correction, the position of the spine and each element of thespine needs to be in alignment and dimensionally correct (in all threedimensions). Thus, in spine surgery, alignment and stability arecritical and often difficult to achieve. It is important for the surgeonto obtain data as he/she corrects the spinal deformity in a minimum ofthree planes. It is also helpful to identify the increasing anddecreasing loads across spinal segments as this is performed.

A system to accomplish this includes more than one sensor array 602according to the invention. In at least one exemplary embodiment, atleast one sensor is placed on or in the cervical, thoracic, and lumbarregions of the spinal column. In a non-limiting example, sensor arrays602 include accelerometers or other position sensing devices such asfiber-optics and RF/EM/US sensors that detect position in all threedimensions. In particular, the placement of sensor arrays 602 onvertebrae is done in a manner where the three-dimensional position datareflects the position of the vertebrae of the spinal column. Sensorarrays 602 are in communication with a computational unit 608 able toprovide three dimensional positioning information of the vertebrae andthe regions of the spine on screen 610. It is noted that sensors 602provides positional information in relation to each sensor and canprovide data corresponding to the rotation of a vertebrae within aregion of the spine or from region to region. As shown, screen 610 candisplay (in varying views) that the vertebrae of the spinal column arealigned along a preferred mechanical axis or an axis corresponding toeach spinal region in three dimensions and that each vertebrae are notrotated in the mechanical axis.

FIG. 7 is an illustration of a spinal column and sensors providingpositional information in accordance with an exemplary embodiment of theinvention. As illustrated, sensor arrays 602 are placed in predeterminedlocations of the spinal column. Sensor arrays 602 in communication withthe computational unit 608 indicate, on the screen 610, curvature of thespine in more than one spinal region. The surgeon can view thedefinition of the pre-surgical alignment in all three planes on thescreen 610. In at least one exemplary embodiment, the surgeon is able torotate the image on the screen to see spine alignment from differentperspectives.

The surgeon uses the system during surgery to further define theachievement of the overall spinal correction angle, and define that thecervical sacral angles are centralized. The surgeon adds bracing,adjusts tensioning, or utilizes other techniques known to one skilled inthe art to maintain the spine in position. Adjusting one area of thespine may disrupt or change positions in other areas of the spinalcolumn. The system provides information to these changes and allows thesurgeon to compensate therefor while the surgery takes place.

FIG. 8 is an illustration of vertebrae having one or more sensor arrays802 in accordance with an exemplary embodiment of the invention. Theillustration shows sensors 802 monitoring adjacent vertebrae. Sensorarrays 802 are placed in or on the vertebrae such that the force orloading between the two vertebrae can be measured. In at least oneexemplary embodiment, the loading can be measured circumferentially todetermine if unequal forces are applied to different areas of thevertebrae. Position measurements using sensors 802 can show whetheradjacent major surfaces of the vertebrae are parallel to one another andperpendicular to the mechanical axis. Similarly, position data fromsensors 802 can indicate if the vertebrae are rotated from an idealalignment. Although load is being measured in the example, sensors 802can measure one or more of at least the following characteristics: load;weight; strain; pressure; wear; position; acceleration; temperature;vibration; density; and distance, to name a few. Thus, substantialbenefit can be provided by the system that combines position, alignment,and relational positioning with measurement of one or more parameters inreal time to aid in correct installation of an orthopedic device. Thesystem also allows sensing of changes in vascular flow and neuralelement function (an example of which includes central and peripheralneuro-modulation systems or sensors) that would aid in detecting changesat the operative site.

FIG. 9 is an illustration of a spinal implant 900 and cage in accordancewith an exemplary embodiment of the invention. In at least one exemplaryembodiment, sensor arrays 902 can be used to define appropriate balanceof the spinal implant 900 during surgery such as a disc implant orfusion cage. In a non-limiting example, sensor arrays 902 are placed ina trial insert 904 for measuring position and load. The load sensors candefine the increased or decreased loads seen above an instrumentedspinal segment. This allows motion preserving implants to be utilizedwithout severely affecting the mechanics of adjacent joint segments.These sensors can be disposed of after surgery or left in to define postoperative angles and loads.

FIG. 10 depicts an example of a sensor deploying instrument 150 having ahandle 151 and a plunger 152 according to the invention. The handle 151and plunger 152 allow the insertion of the sensor 3 that is part of atrocar 153. The trocar 153 can penetrate the cortex and the sensor 3 canbe deployed. FIG. 11 depicts the insertion of the sensor 3 in the femurand FIG. 70 depicts the insertion of the sensor 3 in a vertebra. Thesensor 3 can, then, be decoupled with a coupling mechanism 154, forexample, by an unscrewing or a derotating process. These body areas areused as examples because they are the most commonly affected area withregard to osteoporosis and trauma relating to osteoporosis. The sensor 3can vary in size from several millimeters to over a centimeter. Thesensor 3 can be implanted percutaneously or in an open surgical manner.

The sensor 3 can be part of hardware used in the hip and/or the spine.The sensor 3 can be placed at various depths to allow evaluation of thecortex as well as the travecular bone. With two deployed sensors 3, thedistance between the sensors 3 can be determined at the area of concernand the power field that can be generated. The energy fields can bestandard energy sources such as ultrasound, radiofrequency, and/orelectromagnetic fields. The deflection of the energy wave over time, forexample, will allow the detection of changes in the desired parameterthat is being evaluated.

An exemplary external monitoring sensor system according to FIGS. 10 to12 enables on-contact nightly reads on bone mineral content and density.The sensor system can also enables a transfer of energy waves in avibratory pattern that can mimic load on the bone and lead to improvedbone mineral content and density. The sensors can also send energy wavesthrough or across an implant to, thus, aid in healing of a fracture.

Fracturing of a hip and a spinal vertebra is common with respect toosteoporosis and trauma. FIG. 13 depicts the use of a screw 4 as theinternal sensor. The fracture 160 is spanned by a compression screw 4and the sensors 4 are embedded in the screw 4. The sensors 4 in thescrew 4 can send energy across the fracture site to obtain a baselinedensity reading and monitor the change in density over time to confirmhealing. The sensors 4 can also be activated externally to send energywaves to the fracture itself to aid in healing. The sensors 4 can alsodetect the change in motion at the fracture site as well as the motionbetween the screw and bone. Such information aids in monitoring healingand gives the healthcare provider an ability to adjust weight bearing asindicated. Once the fracture is healed, the sensors 4 shown in FIGS. 14and 15 within the greater trochanter can now be activated to send energywaves to the other two sensors 4. This will enable continued evaluationof bone density. The sensors 4 can be activated with a sensor bed systemwhen the patient is asleep, for example. The energy source and receivercan be attached to the bed undersurface, for example. The receivedinformation can be evaluated every night if needed and sent by standardtelephonic measures to the doctor. The activation of the sensors atnight will enable specific interval readings during treatment ofosteoporosis by various medications.

External and internal energy waves sent with sensors according to theinvention can be used during the treatment of fractures and spinalfusions.

The use of ultrasound, pulsed electromagnetic fields, combined magneticfields, capacitive coupling, and direct electrical current have beenstudied in their affects on the up regulation of growth factors. PulsedUltrasound has shown to activate “integrins,” which are receptors oncell surfaces that, when activated, produce an intracellular cascade.Proteins involved in inflammation, angiogenesis, and bone healing areexpressed. These proteins include bone morphogenic protein (BMP)-7,alkaline phosphatase, vascular endothelial growth factor and insulingrowth factor (IGF)-1. The use of pulsed electromagnetic fields hasshown increased bone healing times in animals. Various waveforms affectthe bone in different ways.

A sensor system using quantitative ultrasound can be used to evaluatecalcaneal bone density externally. The system according to the inventionis attached to the patients' bed and, by using external ultrasound waveforms as shown in FIGS. 14 and 15, the bone density can be evaluated.The use of energy fields have been shown to stimulate the bone healingprocess. Stimulation can be effected with external measures, but use ofinternal sensor systems can change the waveforms and generate avibratory signal that can effectively “load” the bone. This affect isknown, by several orthopedic laws, to strengthen the bone cortex andeffectively be use in the treatment of fractures and osteoporoses and isdepicted in FIG. 14. The sensors in FIG. 14 are in the cortex or canal.The energy waveforms are sent to each other. They can be activated andreceived by an external system or be part of the sensor itself.Similarly, FIG. 15 depicts a vertebral segment in which sensors 4 sendenergy wave forms to each other and to an external receiver. Such asystem/treatment can be used to treat fractures and osteoporosis.

In general, the successful implantation of a device in an organism and,more specifically, in a joint or spine depends on multiple factors. Asdisclosed above, the sensor system can be active for addressingpost-operative complications. Discussed hereinbelow are sensor systemsfor addressing post orthopedic surgery issues with infection and painand factor taken into account when addressing these issues. A firstfactor is the surgeon's desire to implant the device to obtain adequatealignment of the extremity or spine. A second factor is proper seatingof the implant for stability. A third factor is that orthopedic implantstypically comprise more than one component that are aligned in relationto one another. A fourth factor is balance of loading over a rangemotion. A fifth factor, and a more general factor that relates to allimplanted devices, is to minimize infections that can occurpost-operatively.

In a first exemplary embodiment of the invention, a system includes animplantable device and a biological sensor coupled to the implanteddevice. The biological sensor is exposed to the interior of the organismto detect a presence of bacteria and other infecting organisms inproximity to the implantable device post-operatively, for example, afterthe device is implanted. The system can identify potential medicalproblems early after surgical implantation of the implantable device andtake appropriate measures upon identification of the problem. Benefitsof this early diagnosis may reduce post operative re-work withsubstantial benefits in lowering invasive post-operative procedures,decreasing cost, freeing up operating rooms, and minimizing patientstress.

In a second exemplary embodiment, a system includes an implantabledevice having a major surface interior to an organism, a first andsecond electrode (a portion of the interior of the organism beingbetween the first and second electrodes), and a pulsing circuitoperatively coupled to the first and second electrode. Each pulse fromthe pulsing circuit generates an electric field between the first andsecond electrodes. The electric field electroporates one or more cellsof bacteria or an infecting organism in proximity to the generatedelectric field. The system can control a level and a delivery of apharmaceutical agent during the electroporation.

In a third exemplary embodiment, a system includes an orthopedic jointimplant where a portion of the major surface has a plurality ofnanostructures coupled thereto, a biosensor to detect a presence ofbacteria or infecting organisms, and a control circuit operativelycoupled to the at least one biosensor and the nanostructures to enable arelease of the agents contained in the nanostructures. Thenanostructures include agents, hydrogels, antibiotics, or cytoxins toreduce infection by bacteria or an infecting organism and preventbacterial growth in a joint region.

Several implant devices were briefly described earlier, each of whichcan be configured in accordance with the embodiments herein above. Morespecifically, orthopedic devices are shown because they typicallycomprise multiple components that have multiple surfaces internal to apatient. It is noted that orthopedic devices are used herein forillustrative purposes. Various embodiments herein apply to devicesimplanted internal to an organism. Other examples of implantable devicesare monitoring devices, drug delivery devices, pacemakers,defibrillators, to name but a few. A common factor in implanted devicesis that post-operative infections can occur and that the device itselfcan enable the bacteria or infecting organism to thrive.

FIG. 16 is an illustration of a system for preventing infection on animplanted device in accordance with an exemplary embodiment of theinvention. The implantable device can be used in hip, knee, or spineprosthetics or other orthopedic joints as previously described andshown. A platform to monitor and react to an early or late infection isdescribed hereinbelow. In particular, the platform can detect infectionsin an early stage when, if detected, can be treated effectively toeliminate the problem. Detection further eliminates an issue where thepatient with an implant is often unaware of an infection and does notseek help until the bacteria or infecting organism is firmlyestablished. The inventive system also addresses a problem associatedwith the implant itself. The implanted device in conjunction with thelocal biology can provide areas that can harbor, provide sustenance, andfuel growth of the infection.

In at least one exemplary embodiment, system includes one or moresensors that will identify an early infection before it becomes chronic,seeds the device, and prevents the penetration of antibiotics. Mostdevice implants are made of metal or plastics that can be coated by thebacteria allowing them to multiply. In a non-limiting example, a kneeimplant is used to illustrate the system. The system can be applied toother implanted devices or systems.

The knee implant comprises a femoral implant 1606, an insert 1608, and atibial implant 1610. Femoral implant 1606 is coupled to a distal end offemur 1602. Similarly, tibial implant 1610 is coupled to a proximal endof tibia 1604. The insert 1608 is coupled between femoral implant 1606and tibial implant 1610. Insert 1608 provides a bearing surface on whichthe condyles of femoral implant 1606 contact, allowing rotation of thelower leg. In general, at least one biological sensor is coupled to theimplanted device such as a knee implant. In a typical example of theinvention, more than one biological sensor is used to detect bacteria oran infecting organism in a region in and around the implanted device. Itis noted that infection has the highest probability of occurring withina relatively short period of time following the surgical procedure.Moreover, the highest concentration of bacteria will most likely occurin the vicinity of the implant for the reasons discussed above.

As shown, multiple sensors are used to determine if bacteria is presentin proximity to the knee implants. In at least one exemplary embodiment,sensors for detecting the presence are placed in a variety of locationsnear the knee implant. Bacteria is detected in proximity to the distalend femur 1602 by sensors 1612 that are in and part of femoral implant1606. Further coverage of the distal end of femur 1602 is obtained bysensors 1614 placed in or attached to the distal end of femur 1614.Similarly, bacteria is detected in proximity to the proximal end oftibia 1604 by sensors 1616 that are in and part of tibial implant 1610.Additional coverage is achieved by sensors 1618 placed in or attached tothe proximal end of tibia 1604. Sensors 1612 and 1616 also detect apresence of bacteria between femoral implant 1606 and tibial implant1610.

Different methods can be used to determine if an infection is present.The biological sensors 1612, 1614, 1616, and 1618 can detect bacteria orother infecting organism by measuring parameters in proximity to theimplanted devices such as pH, temperature, viscosity, blood flow, achange in material property corresponding to a change in frequency, andby the detection of cell wall markers. For example, the most prevalentbacteria causing post-operative infections in an implanted joint are thestaphylococcus bacteria. In the non-limiting example, synovial fluidaround the joint can be monitored by sensors 1612, 1614, 1616, and 1618.Non-infected synovial fluid will be within predetermined ranges of pH,temperature, and viscosity. Measuring parameters outside thepredetermined ranges can indicate the presence of an infection. Adifferential analysis can also be used. The synovial fluid can bemonitored immediately after the orthopedic device is implanted. Themeasured parameters are then monitored for changes. A significant changein a measured parameter or a change in combination with the absolutemeasured value can be used to indicate the presence of an infection.

Sensors 1612, 1614, 1616, and 1618 can comprise more than one sensortype, A combination of sensors providing more than one measuredparameter can be used in the determination of the presence of bacteriaor an infecting organism. In at least one embodiment, multiple types ofsensors are used in and around the implanted device. A sensor can be asensor array comprising more than one type of sensor integrated into acommon housing. Conversely, separate and different types of sensors canbe placed where needed. Measuring more than one parameter can aid in theidentification of the type of bacteria present or provide earlydetection of an onset of an infection. The pH of synovial fluid willturn increasingly acidic in the presence of bacteria such as thestaphylococcus bacteria. Thus, exceeding a predetermined pH threshold(e.g., equal to or lower than the predetermined threshold value) cantrigger an infection event. Similarly, a change in pH above apredetermined differential value (e.g., a negative change in pH) couldalso be used to trigger the infection event. The temperature of thesynovial fluid will rise with the increasing presence of bacteria insynovial fluid. Thus, exceeding a predetermined temperature or exceedinga predetermined positive differential change in temperature can be usedto trigger the infection event. The viscosity of the synovial fluid willincrease in turbidity, as more bacteria are present. Thus, exceeding apredetermined viscosity or exceeding a predetermined change in viscositycan be used to trigger the infection event. The detection of fluid colorcan also be applied to some applications. For example, synovial fluid isnormally a yellow color that turns to a grey color as the bacteria countrises. Monitoring a change in color can be a useful indication ofbacteria and start of an infection.

In at least one exemplary embodiment, a signal can be sent through thesynovial fluid and the frequency of the signal is monitored over time.In general, a transmitter and receiver are a fixed distance apart. Thesynovial fluid passes between the transmitter and receiver.Post-operatively, the signal will have a characteristic frequencycorresponding to the fluid properties. This characteristic frequency isindicative of a condition where little or no bacteria are present. Abuild up of bacteria in the synovial fluid will change how the frequencypropagates through the fluid. In at least one exemplary embodiment, achange in propagation time results in a change in the frequency. Thus, achange in frequency can be used to determine the presence of bacteria.

Analysis of a bacterial cell wall is a direct method for determining thepresence of bacteria and the type of bacteria. In particular, a sensorlooks for one or more components of the bacterial cell wall thatcomprises an identifying marker. For example, resonance can be used tobreak apart bacterial cell walls. The components of the cell walls orcell wall fragments in the synovial fluid are detected by the sensor.Detecting the presence of the marker indicates an infection. Theconcentration of the marker can indicate the level of the infection.

A preventative measure can be a local release to the implanted deviceregion of antibiotics, cytotoxins, or other elements to eliminatebacteria and infecting organisms near the joint. The release of themedicine could occur over a predetermined time period shortly aftersurgery to implant the device. This can be done during the criticalpost-surgical period when infection is likely to occur. Local release ofmedicine where the infection occurs allows a much lower dose to be used.The implementation will be discussed in more detail hereinbelow. Sensors1612, 1614, 1616, and 1618 can then be used to monitor a region aroundthe implanted device for bacteria although the preventative measureswould greatly reduce the likelihood of an infection.

Alternatively, it may not be desirable to release medicine (evenlocally) unless an infection is imminent. Harmful bacteria are detectedwhen a measured parameter exceeds the predetermined thresholds ofsensors 1612, 1614, 1616, and 1618. Since bacteria are present, measuresare undertaken to suppress or prevent an infection from occurring. Onemeasure is to send a signal that can be transferred to the doctor orpatient indicating a problem. The doctor can, then, prescribe medicationto the patient that will eliminate the bacteria or infecting organismbefore a severe infection occurs. As mentioned above, the system caninclude a response such as antibiotics and cytotoxins that are releasedin proximity to the joint when infecting bacteria are found to be withinrange of the sensors.

In at least one exemplary embodiment, sensors 1612, 1614, 1616, and 1618comprise a sensor for measuring a parameter, a control circuit,circuitry for wired or wireless communication, and a power source. Thecontrol circuit can be a mixed mode circuit having both analog anddigital circuitry. The control circuit is configured operatively to thesensor and the communication circuitry to manage when measurements aretaken, sending the data for appropriate review or triggering a localresponse. In one embodiment, each sensor has a control circuit,communication circuitry, and a power source. Each sensor can be poweredby a battery or a temporary power source. Alternatively, a singlecontrol circuit can be coupled to sensors 1612, 1614, 1616, and 1618 forreceiving information from each sensor (wired or wirelessly) andtransmitting the measured data to an appropriate client.

In one embodiment, the control circuit includes circuitry to convert thedata to a form that can be transmitted by wire or wirelessly. Forexample, the control circuit can have transmitter/receiver circuitry fortransmitting digital or analog data in a standardized communicationplatform such as Bluetooth, UWB, or Zigbee. In one exemplary embodiment,each control circuit enables each sensor to measure data periodically orby command. Furthermore, the measured data can be stored in memory andsent when appropriate, thereby preventing information from being sent byall sensors simultaneously. A signal can also be generated by eachcontrol circuit and sent when a predetermined threshold of sensors 1612,1614, 1616, and 1618 is exceeded.

The system further includes processing unit 1620 having a screen 1622.Processing unit 1620 is in communication with sensors 1612, 1614, 1616,and 1618. Processing unit 1620 can be a digital processing unit,microprocessor, logic circuit, notebook computer, personal computer, orother similar type device. Processing unit 1620 can control when sensors1612, 1614, 1616, and 1618 take measurements and send data, Measuredparameters from sensors 1612, 1614, 1616, and 1618 can be analyzed byprocessing unit 1620 and appropriate actions taken. For example,processing unit 1620 can notify the patient that a problem exists,notify the hospital/doctor that an infection has been detected, or takelocal action by enabling a release of medicine to eliminate theinfecting organism (if the action was not already taken by the sensors).The data can be displayed on screen 1622 to show the parameters measuredby each sensor such that the location, severity, and infection type isunderstood.

As shown, sensors 1614 and sensors 1618 can be inserted or attachedrespectively to femur 1602 and tibia 1604 of the lower leg. For example,sensors 1614 and 1618 can be placed in a housing that has external screwthreads. The sensors in a screw type housing can then be attached inbone using tools common to an orthopedic surgeon. Alternatively, thesensors can be temporarily attached to the bone, an implant device, or asurgical tool so they can be removed or disposed of. For example, asensor array can be pinned to bone for temporary or permanent use. Thesensors can also be incorporated into the implanted device as describedhereinabove.

FIG. 17 is an illustration of an implanted device having bacteria 1702in synovial fluid 1704 around the artificial joint. A synovial membranesecretes synovial fluid 1704 into a joint space around the joint.Synovial fluid 1704 is a natural lubricant for the contacting surfacesof an articulating joint. The liquid in combination with the artificialjoint create an environment that can sustain and fuel the growth ofbacteria 1702. The synovial fluid 1704 contains glucose, which bacteria1702 can feed on. The surfaces and interfaces of the artificial jointform areas in which the bacteria 1702 can have safe harbor as itmultiplies and becomes established, which ultimately can lead to sepsis.

FIG. 18 is an illustration of a pulsed electric field emitted inproximity to an implanted device in accordance with an exemplaryembodiment. In one embodiment, sensors comprising electrodes creating afield are placed in proximity to the implanted device. The sensors areactivated to generate a pulsed electrical field in the presence ofbacteria 1702 or an infecting organism. The pulsed electric fieldinduces electroporation, which is the act of applying an electricalfield to a cell membrane that raises electrical conductivity andincreases the permeability of the cell plasma membrane. Sensor system1800 will activate a pulsed electrical field between two or more of theelements to increase the permeability of bacteria 1702 within the field.Sensor system 1800 will allow modulation of the pulse electricalamplitude, duration, wave number, waveform, and inter-pulse intervals.The predetermined electrical field strength for a predetermined timeperiod will generate a membrane potential that penetrates the cell wallto be activated. Temperature changes and cellular strength can bemonitored during the electroporation process. The weakened cell membraneis made more permeable so that the bacteria 1702 can readily receiveantibiotics, cytotoxins, or other medicine that can eliminate thebacteria 1702 or an early stage infection. In at least one exemplaryembodiment, the medicine is released locally in proximity to the sensorsand the implanted device.

In a non-limiting example, sensors 1612, 1614, 1616, and 1618 areelectrodes strategically placed to apply an electric field in locationsaround an implanted knee joint and, more specifically, across volumes ofsynovial fluid 1704. Alternatively, a micromachined structure can beused to generate the pulsed electric field. One or more sensorsdetecting a presence of infecting bacteria 1702 can initiate anelectroporation process. A doctor or health care professional could alsoinitiate the process by sending a signal to the control circuits of eachsensor. A control circuit can be used to sequence the pulsing of sensors1612, 1614, 1616, and 1618 such that the synovial fluid 1704 and therebythe bacteria 1702 in proximity to the knee implant, distal end of femur1602, and proximal end of tibia 1604 are subject to electroporation. Thecontrol circuit is operatively coupled to a pulsing circuit in eachsensor for generating a pulsed voltage. A voltage multiplier can be usedto provide a voltage not provided by the power source. In at least oneexemplary embodiment, an electric field of between 0.2 kV/cm to 20 kV/cmis used to induce electroporation. Pulse duration is typically frommicroseconds to milliseconds in length. Pulse shape can also affect theamount of permeability achieved and can be tailored for the specificbacteria 1702 and application.

In at least one exemplary embodiment, two or more components of theimplanted device can be electrodes for the electroporation process. Forexample, in a knee implant, a major surface (or portion thereof) offemoral implant 1606 can be a first electrode. Insert 1608 typicallycomprises a non-conductive material. A second electrode can be embeddedin insert 1608. Similarly, tibial insert can be an electrode. Bacteria1702 in synovial fluid 1704 between and around the implanted deviceswould be subject to a pulsed electric field.

FIG. 19 is an illustration of bacterial response to a field in proximityto an implanted device in accordance with an exemplary embodiment.Sensors 1902 and 1906 are placed on or in proximity to the implanteddevice. A bacteria in a first state 1904 is between sensors 1902 and1906. A pulsed voltage is applied across sensors 1902 and 1906 creatinga momentary electric field. The pulsed electric field disrupts the cellmembrane creating cracks or opening pores of the cell wall to result ina bacteria exhibiting a second state 1908. The openings in the cellmembrane can be either temporary or permanent. The bacteria in thesecond state 1908 have increased permeability from the first state 1904.

The increased permeability of the bacteria in the second state 1908allows the penetration of antibiotics, cytokines, or other medicinesthat can be absorbed through the cell wall to kill the bacteria. Themedicine can be provided to the body by injection, pills, or othercommon measures. In at least one exemplary embodiment, a coating isapplied to the implanted device or a portion of the implanted device ismade of nanostructures that can house hydrogels, antibiotics,cytotoxins, and other elements that, by changing the medium in which thebacteria live, would cause damage to the organism cell wall. Forexample, the nanostructures can be attached to exposed surfaces offemoral implant 1606, insert 1608, and tibial insert 1610 in areasexposed to synovial fluid 1704. The nanostructures would be activated bya biosensor to release the anti-infective elements while the pulsedelectrical field will potentiate uptake by the infecting organism in athird state 1910. Thus, a combination of increased cell wallpermeability and local release of medicine to the infected regionmaximizes delivery into the bacterial cell internal structure. Theefficient delivery of the medicine results in a cell death of thebacteria in a fourth state 1912. In at least one exemplary embodiment,the biosensor can target different regions of nanostructures to releasemedicine, thereby controlling the concentration over time.

A further application of the pulsed electrical field is to destroy thecell wall membrane resulting in the bacteria in a fifth state 1914. Inat least one exemplary embodiment, the electric field is pulsed at aresonant frequency of the bacteria. In resonance, the energy applied tothe cell walls of the bacteria is additive. Resonance destroys the cellwall membrane such that the organism is killed and/or prevented frommultiplying. Reducing the level of the infection by resonant destructionof bacteria allow internal macrophages and lymphocytes to attack theremaining organisms.

As mentioned previously, nanostructures on a surface of the implanteddevice could contain or be formed from hydrogels. The hydrogelnanostructures can be formed as a compartment having an opening that canreceive one or more bacteria. The hydrogel nanostructure can also bemade to attract bacteria. For example, the hydrogel can include achemical that attracts the bacteria. Alternatively, the nanostructurecan be polarized or charged to attract the bacteria.

In at least one exemplary embodiment, a bacteria 1916 enters an openednanostructure 1918 to trap the infective organism. The hydrogel wall ofthe nanostructure 1918 can be modulated by the biosensors (pH) and thesensors electrical impulses as well as other local mediators. Thebacteria 1916 is, thus, identified in nanostructure 1918 and thehydrogel walls collapse to contain bacteria 1916 in a closednanostructure 1920. Bacteria 1916 cannot multiply or obtain sustenancewhile contained in nanostructure 1920 and undergo cell death 1922.

It should be realized that a substantial benefit is achieved by having asmart implant that recognizes infection and activates the release ofanti-infective elements that will, along with the generation of a pulsedelectrical field, lead to cell wall penetration and ultimately death ofthe infecting organism The smart system utilizes bio-sensors,piezo-sensors, micromachined structures, and nanostructures having asmall footprint that can be integrated into an implanted device as wellas attached to parts of the body. This will allow the earliest responseto infection and the potential to eradicate the infection without theneed for surgical intervention or implant removal.

A post-operative pain inhibitor (PPI) is described below that integratesperipheral nerve inhibition in the local post-operative field of theimplanted joint. The PPI is a pain modulation system that can be used inconjunction with the skeletal system and, more specifically, with anartificial joint implantation. For illustrative purposes, a knee implantand a hip implant are used to show the operation of the pain inhibitorsystem. A knee implant is known for being one of the more painfulimplant surgeries. In general, the PPI is used to alleviate pain relatedto the skeletal system and can be used for joint implants such as, butnot limited to, knee, hip, shoulder, spine, ankle, wrist, prostheticdevices, articulating, and non-articulating bone structures.

FIG. 20 is an illustration of a post-operative pain inhibitor system2000 for post-operative pain treatment of a skeletal system. In anon-limiting example, a lateral view of a leg is illustrated after aknee replacement surgery has been performed. At least one incision inskin 2001 is used to expose the joint region. The incision gives accessto a femur 2002 and a tibia 2003. A knee prosthesis or joint implant2010 typically comprises a femoral implant, an insert, and a tibialimplant. A distal end of a femur 2002 is prepared and receives thefemoral implant. In a full knee replacement, the femoral implant has twocondyle surfaces that mimic a natural femur. The femoral implant istypically made of a metal or metal alloy. Similarly, a proximal end oftibia 2003 is prepared to receive the tibial implant. The tibial implantis a support structure that is fastened to the proximal end of tibia2003 and is usually made of a metal or metal alloy. An insert is fittedbetween the femoral implant and tibial implant. In the full kneereplacement, the insert has two bearing surfaces in contact with the twocondyle surfaces of the femoral implant that allow rotation of the lowerleg under load. The tibial implant retains the insert in place. Theinsert is typically made of a high wear polymer that minimizes friction.

Post-operative pain inhibitor system 2000 comprises a controller 2032coupled to topical leads 2027 and percutaneous leads 2025. System 2000can address pain control during and after joint replacement. Painaffects a patient's recovery and hinders early joint function. Commoneffects of pain following total knee replacements include depression,tachycardia, insomnia, reflex muscle spasm and sometimes chronicregional pain syndromes. Research has shown that pre-operative paincontrol has a positive effect on the severity of pain post-operatively.Intra-operative anesthetic control is critical. Narcotic medication isstill needed for joint implants and especially for total kneereplacements. Pain control is variable and the common side effects(nausea, vomiting, itching, ileus, confusion, respiratory depression)often interfere with rapid recovery. Post-operative pain inhibitorsystem 2000 can reduce reliance on other pain control methods or be usedin conjunction with the methods to deliver a more consistent and higherlevel of pain reduction.

In at least one exemplary embodiment, one or more leads are placed inproximity to the operative field of the implanted joint. Controller 2032is shown connected by wire to topical lead 2027 and percutaneous leads2025. Controller 2032 provides a signal to leads 2025 and 2027, whichare used to transfer pulses of electrical energy to stimulate peripheralnerve fibers to inhibit or block a pain signal, thereby reducing thepain perceived by the patient. Either type of lead may be used, or bothtypes may be used in combination, to achieve adequate pain control.

In general, low amplitude current is used to stimulate the peripheralnerve fibers. Topical lead 2027 and percutaneous leads 2025 are currentinjecting components that receive a signal from controller 2032. Topicalleads 2027 are placed on a surface of skin 2001 to make electricalcontact. Percutaneous leads 2025 include a contact region that puncturesor couples through the outer skin layer to make contact. Leads 2025 and2027 are attached to a predetermined position on the patient's body,which is typically in the vicinity, but is not limited to, the operativefield where the orthopedic device was implanted and a peripheral nervefiber.

The lateral view of the leg illustrates two embodiments of a wiredelectrical connection from neuro-stimulator circuitry of controller 2032to stimulate peripheral nerves for the inhibition of pain. A firstembodiment comprises a placement of topical leads 2027 with a wiredconnection to controller 2032. The second embodiment is the placement ofa percutaneous lead 2025 with a wired connection to controller 2032. Inboth cases, the electrical pulses travel through external wires toterminate in the lead affixed to the patient's skin 2001. In the case ofthe knee implant, leads 2025 and 2027 are shown contacting skin 2001 inproximity to the implanted knee. Leads 2025 and 2027 provide anelectrically conductive contact to the skin in which to direct thecurrent to the peripheral nerve fiber. The low-amplitude pulsed currentprovided by the neuro-stimulator circuitry of controller 2032 blocks thepropagation of body generated action potentials.

Pain signals are carried by small, slow conducting peripheral nervefibers (C-fibers). The pain signals can be blocked by stimulation of thelarge diameter, rapidly conducting peripheral nerve fibers (A-fibers).The balance between A-fibers and C-fibers determines the degree of pain.Stimulation of A-fibers by a variety of stimuli (scratching, pressure,vibration, or electrical stimulation) with little or no stimulation ofC-fibers will close the gate. Thus, controller 2032 in conjunction withleads 2025 and 2027 stimulate the A-fibers with a current pulse to closethe gate and block the propagation of pain signals carried by theC-fibers, thereby reducing perceived pain by the patient.

In at least one exemplary embodiment, a bipolar electrode device can beused to electrically contact skin 2001 and deliver a signal to inhibit abody generated pain signal propagating in a peripheral nerve fiber. Thebipolar electrode device corresponds to leads 2025 and 2027. The bipolarelectrode device has an anode and a cathode. In a non-limiting example,the anode of the bipolar electrode device is placed in close proximityto the peripheral nerve fiber and the operative field. The cathode ofthe bipolar electrode device is placed away from the anode in a regionof low sensitivity. Sufficient energy is provided by controller 2032 tohyperpolarize the peripheral nerve fiber.

Alternatively, a tri-polar electrode device can be used to selectivelyblock the propagation of body generated action potentials travelingthrough a nerve bundle. The tri-polar electrode device corresponds toleads 2025 and 2027. The tri-polar electrode device comprises a firstanode, a second anode, and a cathode. In a non-limiting example, thecathode is placed between the first and second anodes. A pulse isprovided to the peripheral nerve fiber from both anodes. The cathode canbe placed non-equidistant between the anodes. The signals provided byeach anode can be different. The tri-polar electrode generates auni-directional action potential to serve as collision block withbody-generated action potentials representing pain sensations in thesmall-diameter sensory fibers of a peripheral nerve fiber.

In at least one exemplary embodiment, controller 2032 is accessible tothe patient. It should be understood that each patient is different andeach will have varying ability to cope with pain. Furthermore, placementof the leads 2025 and 2027 and the conducting distance will also vary.In a non-limiting example, controller 2032 couples to a belt that can bewrapped and held at the waist of the patient. Controller 2032 includescontrols such as dials, switches, a keyboard, a touch panel, a touchscreen, or a wireless interface. The controls on controller 2032 areused to modify the signal provided to leads 2025 and 2027. The controlsof controller 2032 are coupled to a logic unit, a signal generator, apower source, and communication circuitry to generate electricalimpulses tailored to an individual's need for appropriate pain relief interms of pulse frequency, pulse width, and pulse amplitude. Thus, asignal provided by system 2000 can be tailored for the individual.Controller 2032 can include a digital signal processor, amicroprocessor, a microcontroller, logic circuitry, and analog circuitryto generate the appropriate signal. The post-operative pain inhibitor(PPI) comprising controller 2032 and leads 2025 and 2027 integrateselectrically mediated pain relief and can be controlled by the patientand modify the pulse amplitude, width, wave shape, repetition rate, andzone migration frequency as it relates to their pain threshold. In atleast one embodiment, leads 2025 or 2027, or other sensing structures incontact with the patient's body, can be a device to monitorperspiration, monitor heat, modify impulses to affect swelling, monitorEMG integration, and monitor inflammatory markers.

FIG. 21 is an anteroposterior view of a leg in accordance with anexemplary embodiment. The anteroposterior view illustrates positioningof the post-operative pain inhibitor system 2000 in relation to the leg,the operative field, and the joint implant 2010. Controller 2032 isattached by a belt to the patient. Controls of controller 2032 areeasily accessible to the patient to modify the signals output byneuro-stimulator circuitry residing therein. Topical leads 2027 andpercutaneous leads 2025 are electrically coupled to skin 2001 to providea signal to peripheral nerve fibers. Topical lead leads 2027 areattached and positioned in proximity to femoral implant 2012 on both themedial and lateral sides of the knee. Percutaneous leads 2025 includes apoint that punctures the skin 2001 (for better contact) and arepositioned in proximity to tibial implant 2014 on both the medial andlateral sides of the knee. Topical leads 2027 and percutaneous leads2025 are within the operative field of the implanted joint. Both typesof leads 2025 and 2027 can be used to transfer pulses of electricalenergy and stimulate peripheral nerve fibers to inhibit propagation ofbody generated action potentials related to pain. As shown, leads 2025and 2027 are connected to controller 2032 by a wire. Controller 2032outputs electrical pulses that travel through the external wires to anattachment point on each of leads 2025 and 2027. Controller 2032 isportable and can be powered by a wired-power supply, a battery, arechargeable battery, or other powering scheme. The portability allowsthe patient to actively use post-operative pain inhibitor system 2000during a rehabilitation process.

FIG. 22 illustrates an anteroposterior view of a post-operative paininhibitor system 2000 for post-operative pain treatment of the skeletalsystem in accordance with an exemplary embodiment. The anteroposteriorview illustrates positioning of the post-operative pain inhibitor system2000 in relation to the leg, the operative field, and the joint implant2010. Controller 2032 is attached by a belt to the waist of the patient.Controls of controller 2032 are easily accessible to the patient tomodify the signals output by neuro-stimulator circuitry residingtherein. Subcutaneous leads 2026 underlie skin 2001 and can bepositioned close to peripheral nerve fibers to enhance the efficacy ofpain modulation. Subcutaneous leads 2026 can be placed in the tissueduring the implantation of femoral implant 2012 and tibial implant 2014respectively to femur 2002 and tibia 2003. The surgeon can view theoperative field and map the region for optimal placement of subcutaneousleads 2026 resulting in lower power utilization and better pain control.In a non-limiting example, leads 2026 are shown positioned in proximityto femoral implant 2012 on both the medial and lateral sides of the kneeand in proximity to tibial implant 2014 on both the medial and lateralsides of the knee.

In at least one exemplary embodiment, a transmitter/receiver 2043 isused to communicate to controller 2032 and subcutaneous leads 2026.Transmitter/receiver 2043 is in a housing affixed to skin 2001 inproximity to leads 2026. Transmitter/receiver 2043 can includeneuro-stimulator circuitry to generate a signal for blocking propagationof body-generated action potentials. In at least one exemplaryembodiment, controller 2032 is in wireless communication withtransmitter/receiver 2043. Controller 2032 includes an interface toallow the patient to adjust the pulse amplitude, width, wave shape,repetition rate, and zone migration frequency in conjunction withtransmitter/receiver 2043. Alternatively, transmitter/receiver 2043 canbe wired to controller 2032. Transmitter/receiver 2043 radiates pulsesof electrical energy to an implanted conductor with one or moresubcutaneous leads 2026 positioned in the vicinity of femoral implant2012 and tibial implant 2014 to provide effective peripheral nervestimulation. In an alternate embodiment, a hub 2045 can be affixed tothe patient's skin 2001. Hub 2045 is directly connected to an implantedconductor with one or more subcutaneous leads 2026 positioned in thevicinity of femoral implant 2012 and tibial implant 2014 to provideeffective peripheral nerve stimulation.

FIG. 23 is a lateral view of post-operative pain inhibitor system 2000in accordance with an exemplary embodiment. The lateral view illustratespositioning of the post-operative pain inhibitor system 2000 in relationto the leg, operative field, and joint implant 2010. Controller 2032 isattached by a belt to the patient, e.g., at the waist. Controls ofcontroller 2032 are easily accessible to the patient to modify thesignals output by neuro-stimulator circuitry residing therein.Subcutaneous leads 2026 underlie skin 2001 and can be positioned closeto peripheral nerve fibers to enhance the efficacy of pain modulation.In a non-limiting example, leads 2026 are shown positioned in proximityto femoral implant 2012 on both the medial and lateral sides of the kneeand in proximity to tibial implant 2014 on both the medial and lateralsides of the knee. In a non-limiting example, leads 2026 are shownpositioned in proximity to femoral implant 2012 on both the medial andlateral sides of the knee and in proximity to tibial implant 2014 onboth the medial and lateral sides of the knee.

FIG. 24 illustrates an anteroposterior view of a post-operative paininhibitor system 2000 for post-operative pain treatment of the skeletalsystem in accordance with an exemplary embodiment. Controller 2032 isattached by a belt to the patient, e.g., at the waist. Controls ofcontroller 2032 are easily accessible to the patient to modify thesignals output by neuro-stimulator circuitry residing therein. In atleast one exemplary embodiment, system 2000 includes an addition ofintraosseous leads 2022 to enhance the efficacy of pain modulation.Intraosseous leads 2022 are respectively coupled to femur 2002 and tibia2003. In a non-limiting example, intraosseous leads 2022 can be attachedto or inserted in bone during the implantation of an orthopedic joint.In general, intraosseous leads 2022 are attached to bone of the skeletalsystem in proximity to a peripheral nerve fiber.

In at least one exemplary embodiment, topical leads 2027 can includetransmitters to radiate pulses of electrical energy to implantedintraosseous leads 2022. Topical leads are connected by wire tocontroller 2032. Topical leads 2027 are placed in proximity tointraosseous leads 2022. More specifically, one or more topical leads2027 having transmitters are positioned on skin 2001 of the patient inproximity to the distal end of the femur 2002 where a first intraosseouslead 2022 resides. Similarly, two additional topical leads 2027 havingtransmitters are positioned on the skin 2001 of the patient in proximityproximal end of tibia 2003 where a second intraosseous lead 2022resides. Each topical lead 2027 radiates pulses of electrical energy toan implanted conductor within intrasseous leads 2022. The pulsedelectrical energy is received by intraosseous leads 2022 and conductedwithin the bone to create an operative field stimulating the peripheralnerve fiber to block propagation of body generated action potentialscorresponding to pain. The patient can change or modify the signalprovided to intraosseous leads 2022 by modifying pulse amplitude, pulsewidth, wave shape, repetition rate, and zone migration frequency usingcontroller 2032 thereby affecting perceived pain to the patient andtailoring the signal for the individual.

Alternatively, intraosseous leads 2022 can include atransmitter/receiver and a power source such as a battery. An externalpowering coil could also be used to energize intraosseous leads 2022 orto recharge the battery. Intraosseous leads 2022 can be in wirelesscommunication with topical leads 2027 or controller 2032. Using lowamplitude current pulses to block the body generated action potentialssystem 2000 could be operated over a significant period of time.

FIG. 25 is a lateral view of post-operative pain inhibitor system 2000in accordance with an exemplary embodiment. The lateral view illustratespositioning of the post-operative pain inhibitor system 2000 in relationto the leg, operative field, and joint implant 2010. Controller 2032 isattached by a belt to the patient, e.g., at the waist. Controls ofcontroller 2032 are easily accessible to the patient to modify thesignals output by neuro-stimulator circuitry residing therein.Intraosseous leads 2022 are attached to femur 2002 and tibia 2003 closeto peripheral nerve fibers to enhance the efficacy of pain modulation.In a non-limiting example, leads 2027 are shown positioned in proximityto the distal end of femur 2002 and proximal end of tibia 2003 on boththe medial and lateral sides of the knee. Controller 2032 is in wiredcommunication with topical leads 2027 while topical leads are inwireless communication with intraosseous leads 2022 as describedhereinabove.

FIGS. 26a and 26b are illustrations of a prosthetic component havingintegrated electrical leads to provide a signal to a peripheral nervefiber to reduce post-operative pain. In a non-limiting example, theprosthetic component is a femoral implant. In general, a distal end of afemur is prepared and shaped to receive a femoral implant. In at leastone exemplary embodiment, a profile of the femoral implant is shapedsimilar to existing implants being offered such that the device can beinstalled using procedures and practices known to the surgeon. Althoughshown as femoral implant, the principles and structures described hereincan be applied to a wide range of orthopedic prosthesis as well as otherimplanted medical devices.

An antereoposterior view of the femoral implant is shown. Theillustration is viewed towards the condyle surfaces of the femoralimplant. Circuitry 2044, within or underlying peg lugs 2019 is coupledwith leads 2020 through an electrical interconnect. In a non-limitingexample, the interconnect can be wire, flex interconnect, or othersuitable electrically conducting material. The interconnect connectsfrom peg lugs 2019 to leads 2020. Leads 2020 are exposed on the surfaceof the prosthetic component. Leads 2020 are positioned around aperipheral surface at a distal end of the femoral implant. The locationis such that leads 2020 are exposed through most or all of a lower legrotation. In at least one exemplary embodiment, peg lugs 2019 extendinto an interior surface of the femoral implant. The lateral view offemoral implant illustrates peg lugs 2019 extending from the surface ofthe femoral implant. The femoral implant is C-shaped having an outersurface that mimics a natural condyle surface. The interconnect isplaced overlying or interior to the internal surface of the femoralimplant connecting peg lugs 2019 to leads 2020.

Many neuro-stimulation procedures require precise positioning ofelectrical leads. Similarly, an orthopedic joint implant requiresprecise positioning of the prosthesis components to the skeletal systemcorresponding to location, distance, relational bone-to-bonepositioning, balance, and alignment. Integration of leads 2020 into aprosthesis component takes advantage of this precise positioning withinthe body that is a very repeatable and consistent procedure. Thus,integration of leads 2020 on the surface of a prosthetic component, orcomponents, or within prosthetic components, enables accurate placementof the leads 2020 automatically with the same high level of accuracy asthe placement of the prosthesis itself. There is no added surgical timeto incorporate the post-operative pain inhibitor because the inhibitoris incorporated in the implant thereby minimizing stress on the patient.Moreover, this reduces cost because the device can be implementedwithout requiring the assistance of a neurosurgeon. Ultimately, patientbenefits including less post operative pain (under user control) andfaster recovery are achieved with minimal impact to the complexity,cost, and length of the surgery.

Circuitry 2044 can further comprise additional circuitry that is placedin femoral implant 2012, for example, sensors and circuitry as describedherein. Circuitry 2044 can process a received signal from a controlleras described herein to support driving leads 2020 to output a pulsedsignal appropriate to stimulate a peripheral nerve fiber in proximity toleads 2020 to block a body generated pain signal. The pulsed signaloutput by leads 2020 can be processed or modified in different ways. Ina first embodiment, processing by circuitry 2044 is minimal with leads2020 directly connected to neuro-stimulator circuitry external to thepatient through a transcutaneous lead. The neuro-stimulator circuitrycan be located in the controller or on or near the transcutaneous lead.In a second exemplary embodiment, one or more topical leads having atransmitter is connected to neuro-stimulator circuitry external to thepatient. The topical leads are affixed to the skin of the patient inproximity to femoral implant 2012. Pulses of electrical energycorresponding to a signal provided to the peripheral nerve fiber arecoupled wirelessly to circuitry 2044 integrated into the femoralcomponent 2012. In a third exemplary embodiment, circuitry 2044 canfurther comprise a power source and neuro-stimulator circuitry tocontrol pain under control of the patient controller. Theneuro-stimulator circuitry is located in the femoral implant and cangenerate appropriate waveforms under patient control to stimulate theperipheral nerve fibers to reduce pain.

In at least one exemplary embodiment, circuitry 2044 is integratedwithin the femoral component and positioned within or underlying peglugs 2019. A receiver circuit of circuitry 2044 can be embedded withinthe femoral component to wirelessly couple electrical energy radiated byan external source, such as, but not limited to, an induction loop orantenna. The energy received by the induction loop or antenna can becoupled directly to transmitter circuitry of circuitry 2044 that isprovided to leads 2020 to be radiated to the peripheral nerve fiber.Circuitry 2044 can further comprise an energy storage capacity thatincludes, but is not limited to, a battery, a capacitor, asupercapacitor, an ultracapacitor, or other measures for continuousreception of external energy. The embedded receiver can be coupled tothe energy storage capacity to power circuitry 2044 and morespecifically neuro-stimulation circuitry in the femoral implant. Theoutput of the neuro-stimulation circuitry is coupled to the leads 2020to provide the pain blocking waveform to the peripheral nerve fiber.

Another variation is the integration of an intraosseous lead or leadsinto the tip or tips of the peg lugs 2019. The intraosseous leads can beincluded in addition to the leads on the perimeter of the femoralimplant to supplement coupling of the stimulation signal to theperipheral nerve fiber. Intraosseous leads can also be used in place ofthe leads 2020 to output a signal that stimulates the peripheral nervefiber. The intraosseous leads are under the control of the controller asare leads 2020.

FIG. 27 is an illustration of components of a post-operative paininhibitor system 2000 integrated into a number of prosthetic components.As mentioned previously, incorporating leads into an orthopedic implantcomponent to stimulate peripheral nerve fibers for reducing pain isbeneficial because of proximity to the operative field and peripheralnerve fibers as well as the precise positioning of the component. Theremay be situations where patients require multiple joint prostheses toraise their quality of life. In such instances, post-operative paininhibitor system can be used in conjunction with each implantedcomponent. In at least one exemplary embodiment, a single patientcontroller 2032 can control each implanted component having integratedleads to affect body generated potentials in proximity to each implantedregion.

A leg is illustrated having both a hip implant 2017 and a knee implant2014. The knee implant 2014 has been described in detail hereinabove. Ahip replacement typically comprises a cup 2011, a bearing 2711, and afemoral implant 2013. In at least one exemplary embodiment, cup 2011comprises metal or other material of high strength. The surgeon reamsout the acetabulum area of the pelvis to fit cup 2011. The fitting ofcup 2011 requires precise positioning in the reamed out acetabulum andis typically a compression fitting. The bearing 2711 is then fitted intocup 2011 for providing a low friction low wear surface in which afemoral head of femoral implant 2013 is fitted. The bearing 2711typically comprises a polymer material such as ultra high molecularweight polyethylene. In general, a predetermined amount of surface areaof femoral head is in contact with the surface of bearing 2711 tominimize loading and wear on the material. The surgeon prepares femur2002 to receive and retain femoral implant 2013. Femoral implant 2013 isfastened into a proximal end of femur 2002. Femoral implant 2013comprises a strong lightweight material and typically comprises a metalor metal alloy. The hip and knee replacement components are selected tobe formed of biologically compatible materials.

Femoral implant 2012 and tibial implant 2014 of the knee implant includecircuitry and leads to stimulate peripheral nerve fibers in proximity tothe operative field of the knee. Similarly, femoral implant 2013includes circuitry and leads to stimulate peripheral nerve fibers inproximity to the operative field of the hip. As disclosed above,controller 2032 is operatively coupled to provide a signal to the leadsof femoral implant 2013, femoral implant 2012, and tibial implant 2014.Controller 2032 further provides patient control of the signal providedto each implant thereby allowing the patient to tailor the signalwaveform to minimize perceived pain in the knee and hip regions. Theanteroposterior view illustrates the relative positions of cup 2011,femoral implant 2013, femoral implant 2012, and tibial implant 2014. Theexample illustrates post-operative pain inhibitor system 2000 havingmore than one active component but is not limited to multiple deviceapplications.

FIG. 28 is a lateral view of post-operative pain inhibitor system 2000in accordance with an exemplary embodiment. The lateral view illustratespositioning of the post-operative pain inhibitor system 2000 in relationto the leg, operative field, and joint implant. Controller 2032 isattached by a belt to the waist of the patient. Controls of controller2032 are easily accessible to the patient to modify the signals outputby neuro-stimulator circuitry residing therein. The lateral viewillustrates femoral implant 2013 in a hip region. It also illustratesfemoral implant 2012 and tibial implant 2014 in the knee region. Theimplants have leads that are exposed in periodic spacingcircumferentially around the implant to maximize signal coverage.Alternatively, the leads can be placed in specific locations that are inproximity to a peripheral nerve.

FIG. 29 is an illustration of hip prosthesis 2017 in accordance with anexemplary embodiment. Each leg has femoral implant 2013 coupled to aproximal end of femur 2002. Each femoral implant 2013 includes leads forcoupling to a peripheral nerve fiber in proximity to the joint implant.As disclosed hereinabove, femoral implant 2013 can house circuitry and apower supply. Controller 2032 is coupled to the leads of each femoralimplant for providing a signal. The signal can be controlled by thepatient. The leads of each implant output the signal to block bodygenerated action potential in the peripheral nerve corresponding to apain signal. Controller 2032 can modify the signal under user control toeach femoral implant 2013 to a waveform that minimizes perceived painfor each leg in proximity to the hip region.

In general, an invasive procedure such as hip surgery causes chemicalsin the body to be released due to the incision and subsequent damage tothe surrounding tissue as the bone is modified and the implants are putin place. The bodily generated chemicals greatly sensitize the localnociceptors causing substantial pain to the patient. Gate theory impliesthat the bodily generated action potentials propagating to theperipheral nerve fibers can be opened or closed. Post-operative paininhibitor system 2000 reduces the propagation of the signals bystimulating the peripheral nerve fibers to close the gate. As mentionedpreviously, the signal coupled to the peripheral nerve fibers are lowcurrent pulses. In general, a typical frequency of the pulses is in therange of 200 Hz to 20,100 Hz. One exemplary beneficial frequency isapproximately 10,000 Hz.

The circuitry placed in femoral implant 2013 comprises a power source,such as a battery and electronic circuitry to energize electrical leadsor to radiate electrical stimuli into the field of stimulation. Thelatter circuitry is referred to as a transmitter. Wireless nervestimulators can be powered by receiving externally generated electricalenergy as input to the transmitter. This receiving circuitry is referredto as a receiver. The provided energy can be continuous or intermittent.If the energy is provided intermittently, a capacity for storingelectrical energy can be used such as a battery, a capacitor, or aninductor.

FIGS. 30a and 30b are illustrations of a tibial implant 2014 inaccordance with an exemplary embodiment. The tibial implant 2014 is asupport and retaining structure for the insert of the prosthetic system.Leads 2021, 2023, 2024, and 2028 are integrated into tibial implant2014. The anteroposterior and lateral views of the tibial componentillustrate the placement of the leads 2021, 2023, 2024, and 2028 thatare exposed on the perimeter of the tibial component 2014. The leadscouple to neuro-stimulation circuitry in one of the tibial implant 2014,a housing attached to skin, or in a controller. Leads 2021, 2023, 2024,and 2028 provide signals to peripheral nerve fibers to block bodygenerated action potentials under patient control via the controller asdescribed hereinabove. Circuitry 2044 can be integrated in manylocations within the tibial implant 2014. In one exemplary embodiment,circuitry 2044 is housed in stem 2052 of tibial implant 2014.

In at least one exemplary embodiment, an intraosseous lead or leads arepositioned on or integrated within the tip (not shown) of the stem 2052of the tibial implant 2014. In one exemplary embodiment, theintraosseous leads are in addition to leads 2021, 2023, 2024, 2028 onthe perimeter of the tibial component 2014. In a second exemplaryembodiment, the intraosseous leads can be used in place of one or moreleads 2021, 2023, 2024, and 2028. The intraosseous leads provide aconductive field of operation that provides effective peripheral nervestimulation.

FIGS. 31a and 31b are illustrations of a cup implant 2011 and a femoralimplant 2013, respectively, in accordance with an exemplary embodiment.Cup implant 2011 is also known as an acetabulum component. Theanteroposterior view of femoral implant 2013 illustrates exposed leadspositioned circumferentially and in different areas of implant 2013. Theleads are connected by wire to circuitry 2044 that can be formed in,internal to, or external to femoral implant 2013. As shown, wires areplaced along the sides of the stem 2018 of the femoral implant 2013 orintegrated within the perimeter of the stem 2018 of the femoral implant2013 of the hip prosthesis. In a non-limiting example, circuitry 2044can be placed in a tip region of femoral implant 2013. Circuitry 2044can include a power source and a transmitter/receiver. Circuitry 2044 inconjunction with the exposed leads generates a field of operation thatprovides effective peripheral nerve stimulation. The nerve stimulationcan be modified using patient controller 2032.

The lateral view of cup 2011 illustrates the placement of leads 2020positioned on or integrated into the perimeter of the cup 2011.Circuitry 2044 can be integrated in many locations within the cup 2011.In a non-limiting example, circuitry 2044 is shown in a central regionof cup 2011.

A further variation includes intraosseous lead or leads positioned on orintegrated within the tip of stem 2018 of the femoral component 2013. Ina first exemplary embodiment, the intraosseous lead or leads areaddition to the leads on the perimeter of femoral implant 2013. In asecond exemplary embodiment, intraosseous leads are used solely tocreate an operative field that provides effective peripheral nerve fiberstimulation in conjunction with external patient controller 2032.

While the above exemplary embodiments of pain inhibitor systemsdescribes leads and sensors related to pain inhibition, these systemsare not limited to pain inhibition and likewise can include, in additionto the pain inhibition leads, all sensor systems described hereinaboveand hereinbelow.

Another exemplary sensor system according to the present inventiondepicts mainly the hip and spine, but can be applied to all skeletalsegments of the body. FIGS. 32, 33, and 41-45 depict variousorientations of sensors according to the invention for treating theknee, hip, and vertebrae.

By way of the device contemplated herein, the surgeon receives measureddata during surgery and post-operatively on the factors listed above. Asone example, accurate measurements can be made during joint implantsurgery to determine if an implant is optimally balanced and aligned.This can reduce operating time and surgical stress for both the surgeonand patient. The data generated by direct measurement of the implantedjoint can be further processed to assess joint integrity, operation, andjoint wear, thereby leading to improved design and materials.

As one example, load balance adjustment can be achieved by soft tissuerelease in response to the assessment. The surgeon or device can reducetension on one or more ligaments to modify loading to a more optimalsituation. In this scenario, the surgeon receives measured data by wayof the device during surgery and post-operatively on the factors listedabove. Consequently, the surgical outcome is a function of the device ascomplemented with the surgeon's abilities but not so highly dependentalone on the surgeon's skill. The device captures the “feel” of how animplanted device should properly operate to improve precision andminimize variation, including haptic and visual cues.

The surgeon utilizes surgical tools to obtain appropriate bony cuts tothe skeletal system and alignment of the implanted device to the bone.The surgical tools are often mechanical devices used to achieve grossalignment of the skeletal system prior to or during an implant surgery.In a non-limiting example, mechanical alignment aids are commonly usedto align the femur, tibia, and ankle optimally. The mechanical alignmentaids are not integrated, take time to deploy, and have limited accuracy.

In at least one exemplary embodiment, a single system comprising one ormore sensors is used intra-operatively, to define implant positioning,achieve appropriate implant orientation, and limb alignment. Inparticular, the system combines the ability to provide positioninformation and measure one or more other parameters (e.g., load, bloodflow, distance, etc.) that provides quantitative data to a surgeon thatallows an implant to be adjusted within predetermined values or rangesbased on the measured data and a database of other similar procedures.The system is designed broadly for use on the skeletal system includingbut not limited to the spinal column, knee, hip, ankle, shoulder, wrist,articulating, and non-articulating structures. For example, the sensorswill enable the surgeon to measure joint loading while utilizing softtissue tensioning to adjust balance and maximize stability of animplanted joint. Similarly, measured data in conjunction withpositioning can be collected before and during surgery to aid thesurgeon in ensuring that the implanted device has an equivalent geometryand range of motion.

It is noted that very little data exists on implanted orthopedicdevices. Most of the data is empirically obtained by analyzingorthopedic devices that have been used in a human subject or simulateduse. Wear patterns, material issues, and failure mechanisms are studied.Although, information can be garnered through this type of study it doesyield substantive data about the initial installation, post-operativeuse, and long term use from a measurement perspective. Just as eachperson is different, each device installation is different havingvariations in initial loading, balance, and alignment. Having measureddata on each installation as well as generating post-operative andlong-term measured data gives significant insight on the operation of adevice under widely varying conditions. In at least one exemplaryembodiment, the measured data can be collected to a database where itcan be stored and analyzed. For example, once a relevant sample of themeasured data is collected, it can be used to define optimal initialmeasured settings, geometries, and alignments for maximizing the lifeand usability of an implanted orthopedic device. In a non-limitingexample, the system disclosed herein can be used by surgeons to measurethe roughed-in implant device (or trial) and then make measurements thatare used to dictate further bony cuts and alignments to fine tune theimplanted device to meet the optimal settings. Furthermore, one or moresensors can be implanted to monitor the joint post-operatively and longterm. The one or more sensors can monitor wear or other parameter thatindicates failure or degradation of the orthopedic device. Thus, the oneor more sensors can indicate a problem or suggest an optimal time toreplace components of the orthopedic device such that only a minimallyinvasive procedure is required, thereby saving cost and stress on thepatient. A further benefit of the system is the use of the measured datato improve materials and orthopedic implant designs based on measuredparameters such as alignment, loading, balance, wear, temperature, andposition.

FIG. 34 is an illustration of a mechanical axis 3400 of a leg inaccordance with an exemplary embodiment. The lower leg comprises a femur3402 and a tibia 3404. Mechanical axis 3400 is typically defined withthe leg in extension. The mechanical axis 3400 of the lower legcorresponds to a straight line drawn from a center of the femoral head3406, through the medial tibial spine 3408, and through a center of anankle 3410. In an optimal mechanical alignment, mechanical axis 3400will pass through the anatomical center of the knee in all threedimensions. This is useful as it can define an alignment in every planeof the knee.

FIG. 35 is an illustration of a plurality of sensors placed on a lowerleg in accordance with an exemplary embodiment. In at least oneexemplary embodiment, the sensors are a component of a system thatidentifies position, relational positioning and measures parameters ofthe knee to aid in fitting of an orthopedic device. In a non-limitingexample, some of sensors can be inserted in bone of the lower leg. Forexample, the sensors can be placed in a housing that has external screwthreads. In at least one exemplary embodiment, the sensors comprise acontrol circuit, circuitry for wired or wireless communication, and apower source (temporary or rechargeable). In a non-limiting example, aposition sensor can include one or more micro electro-mechanical systems(MEMS) accelerometers for measuring spatial orientation and position inthree dimensions. A measurement sensor can include a device formeasuring a parameter such as a strain gauge for measuring load ortemperature sensor. The sensors in a screw-type housing can then beeasily attached in bone using tools common to an orthopedic surgeon.Alternatively, the sensors can be temporarily attached to the bone, animplant device, or a surgical tool so they can be removed or disposedof. The sensors can also be included in the orthopedic implant.

In a non-limiting example, the system comprises positional sensor arrays3502, 3504, 3506, 3508, 3510, and 3512 attached to the skeletal system.The system measures the position of each bone in which a sensor isattached as well as the relational positioning/spatial orientation inthree dimensions. In an accelerometer position sensor system, areference position can be identified and used to determine the locationof other points. Ultrasonic, infra-red, electromagnetic, and fiber opticsensors can be used as well. Sensor array 3502 is coupled to femur 3402.Sensor array 3504 is coupled to tibia 3404. Sensor arrays 3506 and 3508are respectively coupled to the medial malleoulus and lateral malleoulusof the ankle. In at least one exemplary embodiment, sensor array 3506and 3508 are formed in a sensor pad that can be attached to the ankle.The center of ankle 3410 is determined from sensor arrays 3506 and 3508.The center of the femoral head can be determined by pre-operative scansor identified prior to alignment using a technique such as ultrasonicdefinition. Alternatively, one or more identification points can beregistered using electro-magnetic, ultrasonic or infra-red sensors, andused in an alignment procedure to align skeletal structure. Sensorarrays 3510 and 3512 are coupled to a patella 3514 to monitor theposition of patella 3514 in relation to distal end of the femur andproximal end of the tibia 3404.

FIG. 36 is a lateral view illustrating the plurality of sensors placedon the lower leg in accordance with an exemplary embodiment. Sensorarray 3502 provides position information of femur 3402. Sensor array3504 provides position information of tibia 3404. Relational positioninginformation of femur 3402 to tibia 3404 can be indicated on a displayscreen of the system and used in real time during orthopedic implantsurgery. In general, accurate relational positioning can be used toidentify a mechanical axis, to initiate cuts in a predeterminedposition, to check that an installed device is aligned correctly, or toverify a range of motion. Similarly, sensor arrays 3510 and 3512 canprovide relational positioning information of patella 3514 to femur 3402and tibia 3404. Sensor arrays 3510 and 3512 can also includeforce-measuring sensors to determine the loading on patella 3514 suchthat patellar tracking and tension can be adjusted through soft tissuetensioning (and the adjustments measured and viewed). Although notshown, sensor arrays 3502, 3504, 3506, 3508, 3510, and 3512 are incommunication with a processing unit that receives the positional andmeasurement information and displays the information in a format usefulto a surgeon on a screen or display. It is noted that sensors disclosedherein can be temporarily attached. In a non-limiting example, a sensorarray can be taped, glued, or pinned to a location internal or externalto the body. This allows additional flexibility to the placement of thesensors. The sensors can then be removed for reuse or disposed of aftermeasurements have been taken, thereby being out of the way forsubsequent surgical steps if desired.

FIGS. 37a and 37b are lateral views illustrating the lower leg with aplurality of sensor arrays in extension and flexion in accordance withan exemplary embodiment. In at least one exemplary embodiment,accelerometers in sensors 3502 and 3504 provide positional informationand relational positioning. In at least one exemplary embodiment,accelerometers are in integrated circuit form such that a small formfactor can be achieved. Furthermore, accelerometers can be provided thatmeasure all three dimensions. The accelerometers can be integrated withthe control circuit to further reduce sensor array footprint.

The lower leg can be positioned in extension by the surgeon. A screendisplays the relative positioning such that femur 3402 and tibia 3404are positioned corresponding to an actual position of the leg. Forexample, the surgeon places femur 3402 and tibia 3404 in extension suchthat they are both in the same plane. The display of the systemindicates the position of femur 3402 in relation to tibia 3404 and showsan angle of zero degrees (0°) indicating that the leg is in extension.

A measurement of zero degrees describes femur 3402 and tibia 3404 in thesame plane. The lower leg can be aligned to an optimal mechanical axisusing position data from sensor arrays 3502, 3504, 3506, 3508 and alocation of femoral head center 3406. Alternatively, femoral head center3406 can be identified by rotating femur 3402 and using sensor arrays3502 to track the motion. The tracked motion can be use to interpret thelocation of femoral center 3406. The knee center can be defined in theincision. Thus, the mechanical axis of the lower leg can then be definedvery accurately using the sensors by aligning femoral head center 3406,the knee center, and the ankle center 3410. The surgeon then has thebenefit of knowing proper alignment during the course of the implantsurgery. Moreover, the positional relationship can be tracked throughoutsurgery. For example, in an orthopedic device implant, measurements canbe taken over a range of motion to determine and ensure proper fit overthe operational bounds of the device. As shown, sensor arrays 3502 and3504 respectively coupled to femur 3402 and tibia 3404 can indicate thelower leg in flexion. More specifically, sensors 3502 and 3504 indicatethat tibia 3404 is positioned ninety degrees (90°) from a position offemur 3402. Thus, the surgeon can make cuts and adjustments knowing thealignment and the positional relationships of bones of a skeletalstructure are correct.

FIG. 38 is a lateral view of the plurality of sensor arrays incommunication with a processing unit 3806 and a screen 3802 forproviding information in accordance with an exemplary embodiment. In atleast one exemplary embodiment, sensor arrays 3502, 3504, 3506, 3508,3510 and 3512 are in communication with a computer or computationaldevice having processing unit 3806 for processing information from thesensors. For example, processing unit 3806 can be a microprocessor, amicrocontroller, a digital signal processing chip, a mixed signalanalog/digital chip, a logic circuit, a notebook computer, and/or apersonal computer to name but a few. Screen 3802 is coupled to thecomputer for displaying sensor array measurement and positioninformation. In a non-limiting example, screen 3802 and thecomputational device are outside of the surgical zone (or sterile box)in an operating room. In one exemplary embodiment, processing unit 3806and screen 3802 comprises a notebook computer for reasons ofportability, lower cost, and minimizing footprint in the operating room.The notebook computer incorporates a user interface for use by thesurgeon or medical professionals that allow real-time interaction withthe sensor position and measurement information. For example, as an aidto the surgeon, the portion of the skeletal structure having sensorarrays placed thereon can be displayed on screen 3802 to show alignment,position, and relational positioning in real-time as the surgicalprocedure progresses. Thus, the surgeon has a tool that combines bothposition and parameter measurement to aid in ensuring correctpositioning of an implanted device and that the implanted deviceparametrics measure within reason and to allow adjustments to be madeand measured, thereby allowing a surgeon to subsidize qualitativeinformation with quantitative data.

In at least one exemplary embodiment, element 3804 facilitatescommunication between the sensor arrays and processing unit 3806.Element 3804 comprises receive and send circuitry and is incommunication with processor unit 3806 and sensor arrays 3502, 3504,3506, 3508, 3510, and 3512. Element 3804 can be placed in proximity tothe sensors to ensure pick up of the signal. For example, component 3804can be incorporated into a lighting system of the operating room whereit has a direct and unblocked communication path. Alternatively, theelement 3804 can be incorporated into the housing for the computationaldevice or screen 3802 to provide the sensor information to theprocessor. Element 3804 can be directly connected to sensors 3502, 3504,3506, 3508, 3510, and 3512 by wires or fiber optics, for example.Similarly, element 3804 can be connected to processing unit 3806 by wireor fiber-optics, for example. Element 3804 can also be wirelesslyconnected to sensors 3502, 3504, 3506, 3508, 3510, and 3512 and theprocessor using radio frequency, ultrasonic, infra-red, magnetic orother wireless communication methodology.

As mentioned previously, each sensor array is coupled to a controlcircuit. The control circuit includes circuitry to convert the data to aform that can be transmitted by wire or wirelessly. For example, thecontrol circuit can have transmitter/receiver circuitry for transmittingdata in a known format such as Bluetooth, UWB, or Zigbee. In oneembodiment, position and measurement data is taken periodically or bycommand. The data can be stored in memory. The control circuit can beenabled by a received signal from processing unit 3806 to send theinformation stored in memory. Similarly, the control circuit can beenabled to take position and measurement data by processing unit 3806.This enables multiple sensor arrays to be enabled and an orderly processfor collecting data, sending data, analyzing processing the information(using processing unit 3806), and displaying the data on screen 3802 foruse by the surgeon or medical team during surgery.

FIG. 39 is a lateral view of the knee illustrating a knee with a jointimplant and sensors in accordance with an exemplary embodiment. The kneeis used as an example of the system for orthopedic implants to lowercost, reduce stress on the patient, have a small spatial footprint inthe operating room, collect data, aid in tuning the device implant foroptimal geometry, and reduce short term/long term post-operative rework.The system is adaptable for use in all areas of the skeletal system.More specifically, a single system is disclosed for orthopedic surgery,which can provide alignment, positioning, relational positioning,initial conditions, loading, and balance information over the entirerange of motion. Integration into a single system greatly simplifies theprocedure and ensures consistency of results because both qualitative(e.g., surgeon) and measured (quantitative) data can be used to assesseach step of the procedure. Moreover, the data collected can be used toidentify issues before they become problems for the patient and provideinformation for improving the orthopedic device.

There is a general trend to implement solutions that lower health careoperating costs without compromising patient care. One benefit of thesystems according to the invention is that they can be easilyincorporated into orthopedic surgeries because of low cost. The singlesystem does not require a significant capital expense. For example, thecomputational device that houses processing unit 3806 can be a laptopcomputer that can be purchased at low cost instead of a fully customizedsystem. Software corresponding to this application is downloaded to andstored on the laptop computer. Element 3804 can also be coupled to thelaptop computer either wired or wirelessly to support communication ifneeded. In at least one exemplary embodiment, the system is made as adisposable device. In other words, there is almost no capital expenserequired by the hospital or clinic to implement the system, therebyeliminating typical barriers to adopting new technology. Some of thesystem components are incorporated in orthopedic implant trials ortemporarily attached to the skeletal system, these parts can be disposedof after measurements are made or prior to the final implant deviceinstallation. Alternatively, the sensors can be permanently incorporatedinto the skeletal structure and final implant device for post-operativemonitoring and for long term device monitoring.

In a non-limiting example, the implanted device is shown with a trialinsert used to measure and tune the knee joint prior to a final insertbeing installed. The single system comprises any of the sensors orsensor arrays disclosed herein. The single system further comprises afemoral implant 3902, a tibial implant 3904, and a trial insert 3906.Trial insert 3906 measures a parameter such as load over a range ofmotion. In at least one exemplary embodiment, the knee joint is exposedby incision. Alignment of the mechanical axis of the lower leg isachieved as disclosed above with the leg in extension such that thefemoral head center, medial tibial spine, and ankle center are alignedin a straight line using the single system to aid the surgeon. Bony cutsare made utilizing the alignment whereby the distal end of femur 3402and the proximal end of tibia 3404 are shaped for receiving orthopedicjoint implants. Jigs and other orthopedic devices can be used to shapeand aid in the bony cuts. The sensors of the invention can be attachedto the cutting jigs or devices to aid the surgeon in optimizing thedepth and angles of their cuts.

In a non-limiting example, a rectangle is formed by the bony cuts. Theimaginary rectangle is formed between the cut distal end of femur 3402and the cut proximal end of tibia 3404 in extension and in conjunctionwith the mechanical axis of the lower leg. A predetermined width of therectangle is the spacing between the planar surface cuts on femur 3402and tibia 3404. The predetermined width corresponds to the thickness ofthe combined orthopedic implant device comprising femoral implant 3902,trial insert 3906, and tibial implant 3904. Trial insert 3906 isinserted between the installed femoral implant 3902 and tibial implant3904. Trial insert 3906 can have a surface comprising the same orsimilar material as a final insert.

In at least one exemplary embodiment, trial insert 3906 comprises load,accelerometer, and other types of sensors 3912. The sensors 3912 are incommunication with processing unit 3806. Sensors can be placed infemoral implant 3902, trial insert 3906, and tibial implant 3904 thatwork in conjunction with the sensors described herein to define limbalignment, implant-to-implant alignment, and joint kinematics. Ingeneral, the sensors of femoral implant 3902, trial insert 3906, andtibial implant 3904 can measure parameters such as weight, strain,pressure, wear, position, acceleration, temperature, vibration, density,and distance. Trial insert 3906 is used to measure the load on eithercondyle surface of femoral implant 3902 while in extension. In anon-limiting example, the screen of the system (e.g., display 3802) canshow the location of the point of contact for both condyle surfaces ontrial insert 3906 and the load.

Trial insert 3906 can indicate that the loading measurement on bothcondyles is either high, within an acceptable predetermined range, orlow. A loading that measures above a predetermined specification can beadjusted using a thinner final insert. Conversely, a loading thatmeasures below a predetermined specification can be adjusted using athicker final insert. The system can provide an appropriate solutionfrom a look up table (changes in thickness versus measurement to getwithin a predetermined range). Alternatively, trial insert 3906 can beremoved and another trial insert of a different thickness can be used totake a measurement such that a loading in the predetermined range ismeasured. The surgeon can also make a soft tissue adjustment in the casewhere the tension is too high but close to the predetermined range. Asmentioned previously, the system is in communication with processingunit 3806 to record measurements during the surgical procedure.

Balance is a comparison of the load measurement of each condyle surface.Balance correction is performed when the measurements exceed apredetermined difference value. Soft tissue balancing is achieved byloosening ligaments on the side that measures a higher loading. Thesystem provides the benefit of allowing the surgeon to read the reducedloading on screen 3802 of the system with each soft tissue release untilthe difference in loading between condyles is within the predetermineddifference value. Another factor is that the difference in loading canbe due to surface preparation of the bony cuts on either femoral implant3902 or tibial implant 3904. The surgeon has the option of removing boneon either surface underlying the implant to reduce the loadingdifference. In a further exemplary embodiment, trial insert 3906provides position data indicating where each condyle contacts a surfaceof trial insert 3906. Similar to above, the surgeon has the option ofaltering the surface of the distal end of femur 3402 or the proximal endof tibia 3404 to move the contact regions in conjunction with themechanical axis.

As shown in FIG. 39, the lower leg is in flexion with tibia 3404 at aright angle to femur 3402. In general, one or more bony cuts to thedistal end of femur 3402 are made. In particular, a prepared surface atthe distal end of femur 3402 is parallel to the prepared surface oftibia 3404 in this position. Similar to that described above, animaginary rectangle is formed by the parallel surfaces of femur 3402 andtibia 3404 in the ninety-degree flexion position. A predetermined widthof the imaginary rectangle is the spacing between the planar surfacecuts on femur 3402 and tibia 3404 in the flexion position (ninetydegrees). The predetermined width corresponds to the thickness of thecombined orthopedic implant device comprising femoral implant 3902,trial insert 3906, and tibial implant 3904. Ideally, the measured widthis similar or equal to the width of the imaginary rectangle inextension. Load measurements are made with the leg in flexion.Adjustments to the load value and the balance between condyles can bemade by soft tissue release and femoral cuts/implant rotation. Onceadjusted, tibia 3404 can be moved in relation to femur 3402 over therange of motion. The loading can be monitored on the screen over therange of motion to show that the absolute loading on the knee is withina predetermined load range and that the difference in loading betweenthe two condyles is within a predetermined differential value. Should anout-of-range-value condition occur, the surgeon can view the positionwhere it occurs on screen 3802 of the system and can take steps to bringthe condition within specifications. It is noted that, presently, asurgeon does not have the capability of performing such corrections.Finally, as the leg is rotated through the range of motion, a plot ofthe movement of the contact region of either condyle can be displayed onthe screen 3802. The contact region should be within a predeterminedarea. Movement outside the predetermined area can indicate amisalignment or rotation issue, which the surgeon can correct at thistime. The trial insert is removed if the surgeon is satisfied by themeasured data. Femoral implant 3902, a final insert, and tibial implant3904 are then permanently attached to the knee. In at least oneexemplary embodiment, the final insert can have sensors forpost-operative monitoring and long-term monitoring of the implanteddevice.

Sensor arrays 3510 and 3512 on patella 3514 can be used to trackposition and measure a parameter (such as load). Sensor arrays 3510 and3512 work with sensor arrays 3908 in femoral implant 3902. Moving theleg through a range of motion will track patella 3514 in relation tofemoral implant 3902. The system will show patellar movement and loadingon the screen. The surgeon can then use soft tissue adjustments and/or achange in the implant rotation positioning to ensure the patella trackscorrectly (alignment) and that the loading stays within a predeterminedrange (over the range of motion). With each correction, the surgeon canview on the screen how the correction affected patellar tracking andloading until satisfactory results are achieved. It is noted that,presently, surgeons do not have this kind of feedback to makeadjustments.

FIG. 40 is an anteroposterior view of a knee and sensor arrays inaccordance with an exemplary embodiment. The sensor arrays areincorporated for long term monitoring. Femur 3402 is shown having sensorarrays 3502. Femoral implant 3902 is coupled to the distal end of femur3402. Femoral implant 3902 includes sensors 3908. Tibia 3404 is shownhaving sensor arrays 3504. Tibial implant 3904 is coupled to theproximal end of tibia 3404. Tibial implant 3904 includes sensor array3910. An insert 3906 is coupled between tibial implant 3904 and femoralimplant 3902. Two condyles of femoral implant 3902 ride on a bearingsurface of insert 3906. Sensor arrays 3912 of insert 3906 underlying thebearing surface can be used to take measurements as disclosedhereinabove. The sensors of the system work in conjunction withprocessing unit 3806 and communication circuitry to provide data thatcan be used to determine the working status of the implant and tominimize short-term and long-term problems after surgery. In at leastone exemplary embodiment, the patient can return for outpatient reviewof the implant. The sensor arrays of the system can be placed incommunication with processing unit 3806 or another system loaded withenabling software. An analysis of the status of the orthopedic deviceand patient health can be provided and displayed on screen 3802.

Sensors according to the invention are used in multiple orthopedicapplications, including intra-operative joint implant alignment. Sensorsand monitoring devices/systems that can be used include any of thosewell known in the art, such as those described in the Nexense patentsand incorporated herein by reference. Computer assisted surgery is alsocommonplace.

Presently, the use of pins in the femur and tibia, allow arrays to beattached to the bones. Such attachment helps in spatial orientation ofthe knee/hip joint during the operation. These arrays are recognized byinfrared optics or by electromagnetic devices (see, e.g., FIGS. 48 and49) to replay the information into a recognized software system thatallows the surgeon to visualize the joint in a three-dimensional mannerwhile overlaying the implant of choice on the bones. Problemsencountered with the application of such pins are many:

-   -   the need to penetrate bones outside the field of surgery;    -   post-operative pain that might require peripheral nerve blocks        and neuro-modulation and drainage from the pin sites;    -   the possibility of pin loosening during the surgery as well as        blocking the arrays and infra-red light;    -   the pins require the surgeons to change the present positioning        during the procedure, which can be difficult; and    -   the electromagnetic field can be affected by various metals and        instruments that are used in the surgery.

The time associated with inserting the pins, locking the arrays, andregistering the joint topography contributes to a significantly longprocedure duration. There is still a need to individually touch multiplepoints on the femur and tibia to allow the computer to visualize thetopography of the knee. The time for transmission of information fromthe sensors to the receiver also causes a potential delay. Therefore, itwould be desirable to reduce or eliminate each of these problems.

Methods according to the invention include implanting the sensors in thefield of surgery, using the sensors during surgery, and using theimplanted sensors post-operatively to evaluate various desiredparameters.

Moving now to FIGS. 46 and 47, these figures depict one exemplaryembodiment of a handle 170 that can be releasably connected to animplantable sensor body 5. In this embodiment, the handle has anexterior thread that screws into an interior correspondingly threadedbore of the body 5.

FIG. 50 illustrates embedded sensors 6 in the femur and the tibia, andFIG. 51 illustrates sensors 6 in the patella. The ligaments showninclude the medial collateral ligament, the lateral collateral ligament,the anterior cruciate ligament, and the posterior cruciate ligament. Thesensors 6 are implanted prior to surgery percutaneously and/orarthroscopically or intra-operatively through open surgery. FIG. 52depicts a ligament or tendon, FIG. 53 depicts a sensor clamp with acompressive and release handle, FIG. 54 depicts the partial deploymentof the sensor, and FIG. 55 reveals the deployed sensor in the ligament.As shown in the steps depicted by FIGS. 52 to 55, the sensors can beembedded into the ligaments (FIG. 52 illustrates an exemplary ligament)by providing a sensor clamp (FIG. 53) that is placed around the ligament(FIG. 54) and secured thereto (FIG. 55). The sensor clamp (FIG. 53)above has sensors, a handle, and applies a compressive force to themuscular-skeletal system. The sensors can also be embedded into bone asshown later in FIG. 71, for example. Standard radiograph techniques canbe used to guide deployment angle and depth.

The exemplary embodiments of sensors and sensor systems described hereinhave been associated with the dynamic adjustment of trial implants toimprove the implant surgery in a way that maximizes success when thefinal implant is installed. To assist with the dynamic adjustment of theimplants (for example, femoral implant 3902, tibial implant 3904, andinsert 3906) inter-operatively, a distractor tool can be utilized. Thisdistractor tool can be equipped with any of the sensors disclosedherein.

By way of the exemplary distractor device contemplated hereinbelow, thesurgeon receives measured data during surgery, and post-operatively onthe factors listed above. As one example, accurate measurements can bemade during orthopedic surgery to determine if bones or an implant areoptimally balanced and aligned. This can reduce operating time andsurgical stress for both the surgeon and patient. The data generated bydirect measurement can be further processed to assess long-termintegrity based on maintaining surgical parameters within predeterminedranges. The measured data in conjunction with patient information canlead to improved design and materials.

FIG. 56 is a top view of a dynamic distractor 5600 in accordance with anexemplary embodiment. Dynamic distractor 5600 is also known as a dynamicspacer block. Dynamic distractor 5600 is a sensored device that is usedduring surgery of a muscular-skeletal system. Dynamic distractor 5600can be used in conjunction with other tools common to orthopedic surgeryas will be disclosed in more detail hereinbelow. This distractor 5600for example can be used as a ligament tensioning device and/or a dynamicinsert trial to mimic variable thicknesses. In at least one exemplaryembodiment, the system is used during orthopedic joint surgery and, morespecifically, during implantation of an artificial joint. The systemuses one or more sensors intra-operatively to define implant loading andpositioning and to achieve appropriate implant orientation, balance, andlimb alignment. In particular, dynamic distractor combines the abilityto align and measure one or more other parameters (e.g., load, bloodflow, distance, etc.) that provides quantitative data to a surgeon,allowing the orthopedic surgery to be measured and adjusted withinpredetermined values or ranges based on the measured data and a databaseof other similar procedures. The system is designed broadly for use onthe skeletal system including, but not limited to, the spinal column,knee, hip, ankle, shoulder, wrist, articulating structures, andnon-articulating structures.

Dynamic distractor 5600 comprises an upper support structure 5702 and alower support structure 5704. An active or dynamic spacer portion 5620of dynamic spacer block comprises the upper and lower support structures5702, 5704. A lift mechanism 5802 (see, e.g, FIG. 58) couples to aninterior surface of upper support structure 5702 and an interior surfaceof the lower support structure 5704. A handle 5612 couples to the liftmechanism 5802. In one embodiment, handle 5612 is operatively coupled tothe lift mechanism 5802 to change a gap of the spacer block. Handle 5612can also be used to guide dynamic distractor 5600 between regions of themuscular-skeletal system. In general, the upper support structure has asuperior surface 5602 that interfaces with a surface of themuscular-skeletal system. Similarly, the lower support structure has aninferior surface 5706 that interfaces with a surface of themuscular-skeletal system.

In one exemplary embodiment, handle 5612 can be rotated to adjust thelift mechanism 5802 to increase or decrease a gap between the superiorand inferior surfaces of the active spacer block, thereby modifying theheight or thickness of dynamic distractor 5600. In a non-limitingexample to illustrate a disposable aspect of the invention, superiorsurface 5602, the inferior surface 5706, or both surfaces include atleast one cavity or recess 5604, 5606 for housing at least one sensormodule 5608, 5610. The sensor module 5608, 5610 includes at least onesensor for measuring a parameter of the muscular-skeletal system. Forexample, the sensor can measure a force or pressure. As will bedisclosed hereinbelow, the sensor can be disabled so it cannot be reusedand disposed of after the procedure has been performed. In a furtherexample, dynamic distractor 5600 can be placed between two or more bonesurfaces such that the superior surface 5602 and the inferior surface5706 contact surfaces of the muscular-skeletal system related to ajoint. In one embodiment, the sensor is coupled to a surface of themuscular-skeletal system for measuring a parameter when positionedbetween surfaces. Handle 5612 can be rotated to different gap heightsallowing pressure measurements at the different gap heights to generatedata of gap versus pressure.

Handle 5612 further includes an opening 5614, a decoupling mechanism5618, and a display 5616. Opening 5614 is used to receive additionalcomponents of the system that will be described in more detailhereinbelow. Decoupling mechanism 5618 allows removal of the handleduring parts of a surgery to allow access to the muscular-skeletalsystem. Decoupling mechanism 5618 couples to a locking mechanism thatlocks handle 5612 to a shaft of the lift mechanism 5802. Decouplingmechanism 5618 releases the locking mechanism, thereby allowing handle5612 to be removed from dynamic distractor 5600. In one exemplaryembodiment, the locking mechanism is a pin or ball that fits into acorresponding feature 5622 on the shaft of the lift mechanism 5802.Decoupling mechanism 5618 releases or frees the pin or ball from feature5622, thereby allowing removal of handle 5612. Alternatively, decouplingmechanism 5618 can be a hinge or joint that allows handle 5612 to movein a direction that allows greater access by the surgeon to an areawhere the spacer block portion of dynamic distractor 5600 has beenplaced. The display 5616 on handle 5612 can provide a readout of the gapbetween the superior surface 5602 and the inferior surface as handle5612 is rotated to adjust spacing.

In a non-limiting example, dynamic distractor 5600 is adapted for use inartificial knee implant surgery. It should be noted that dynamicdistractor 5600 can be similarly adapted for other orthopedic surgerywhere both distraction and parameter measurement is beneficial. A kneeimplant is used merely as an example to illustrate how dynamicdistractor 5600 can be used in a surgical environment. In at least oneexemplary embodiment, the superior surface 5602 of dynamic distractor5600 includes a first recess or cavity 5604 and a second recess orcavity 5606. In one embodiment, sensor 5608 and 5610 are pre-sterilizedin one or more packages. The packaging is opened prior to or duringsurgery within the surgical zone to maintain sterility. Sensors 5608 and5610 are shown respectively placed in cavities 5604 and 5606 formeasuring a parameter that aids in the surgical procedure. In the kneeexample, sensors 5608 and 5610 include pressure sensors such as straingauges, mechanical-electrical-machined (MEMS) sensors, diaphragmstructures, mechanical sensors, or other pressure measuring devices. Inone exemplary embodiment, a major exposed surface of sensors 5608 and5610 is in contact with the muscular-skeletal system after insertion.Alternatively, one or more layers of material or portions of themuscular-skeletal system can be disposed between sensors 5608 and 5610such that the parameter can be measured or transferred through theintervening layers. A force or pressure applied to the exposed surfacesis measured by sensors 5608 and 5610 while the gap of the dynamicdistractor is adjusted. Alternatively, the lift mechanism 5802 inconjunction with sensors 5608 and 5610 can be set to a predeterminedpressure. The lift mechanism gap increases until the predeterminepressure is reached. From this, a gap height or thickness of dynamicdistractor 5600 is identified to achieve the predetermined pressure.

In at least one exemplary embodiment, sensors 5608 and 5610 aredisposable devices. After measurements have been taken, sensors 5608 and5610 can be removed and disposed of in an appropriate manner.Alternatively, the sensors 5608 and 5610 can be a permanent or integralpart of the superior surface of dynamic distractor 5600. The housing canbe designed to be reused and to withstand a sterilization process aftereach use. The main body of dynamic distractor 5600 as well as sensors5608 and 5610 are cleaned and sterilized before each surgical usage.

Dynamic distractor 5600 in a zero gap (or closed condition) is less than8 millimeters in total thickness for the knee application and can expandusing the lift mechanism 5802 to greater than 25 millimeters. This rangeis sufficient for the majority of artificial knee implant surgeriesbeing performed presently. The spacer portion 5620 of dynamic distractor5600 contains the superior and inferior surfaces 5602, 5706 thatarticulate to at least two bone ends of the muscular-skeletal system. Inthe knee example, the dynamic distractor 5600 is placed between thedistal end of the femur and the proximal end of the tibia. As mentionedpreviously, sensors 5608 and 5610 are in a housing. In one embodiment,the housing includes sensor elements to define the loads on the medialand lateral compartments. The sensored elements can comprise loaddisplacement sensors, accelerometers, GPS locators, telemetry, powermanagement circuitry, a power source and an ASIC, to name a few.

As disclosed above, the spacer portion 5620 of dynamic distractor 5600is placed between the femur and tibia in extension. The dynamicdistractor 5600 is configured with no gap (i.e., minimum height orthickness) or having a gap that can be inserted and removed withouttissue damage. In general, the gap can be increased by rotating handle5612 after insertion, so that the inferior surface of dynamic distractor5600 contacts a prepared surface of a proximal end of a tibia and thesuperior surface contacts the prepared distal end of the femur. Ingeneral, the femoral and tibial cuts in extension are made parallel toone another. Similarly, the femoral cut in flexion is made parallel tothe prepared end of the tibia. The gap is measured to determine acombined thickness of the implants with the leg in extension. Theprepared ends of the tibia and femur can be checked for alignment withthe mechanical axis at this time as will be disclosed in detail below.

Typically, the surgeon selects the artificial components based on thecross-sectional size of the prepared bones. The variable component ofthe implant surgery is the final insert. The final insert has one ormore bearing surfaces for interfacing with a femoral implant. In oneembodiment, the measured gap height created by dynamic distractor 5600is used to define an insert thickness or height. The thickness of afinal insert can change during surgery as further bone cuts or tissuetensioning occurs. Dynamic distractor 5600 can be used during surgery tomeasure loading and gap height after each bone modification or after anorthopedic component has been implanted.

Dynamic distractor 5600 can also be used to obtain an optimal balance.Balance is related to the measured loading between two or more areas.The measured values can than be adjusted to a predetermined relationshipand within a predetermined value range. In the knee example, balance isassociated with the differential pressure applied by each condyle on thebearing surfaces of the implant. Ideally, a predetermined surface areaof the femoral implant condyle contacts the bearing surface todistribute the load and minimize wear. In a non-limiting example, apredetermined relationship between measured values by sensors 5608 and5610 of dynamic distractor 5600 is maintained after implantation of theartificial components. In one embodiment, the balance of the knee ismaintained by having the measured load in each compartment approximatelyequal. A method to balance the loading of the compartments is throughligament release on the side having the larger loading value. Ligamentrelease reduces loading primarily on the adjacent compartment. Theloading can be read off a display on dynamic distractor 5600, allowingthe surgeon to view the change in loading and the differential valuewith each release. The lift mechanism 5802 provides sufficient roombetween the superior and inferior surfaces of dynamic distractor 5600for a surgeon to perform a release procedure without removing thedevice. A next greater thickness of an insert can be selected should theabsolute loading value on each condyle fall outside the predeterminedrange due to the soft tissue release. Handle 5612 can be rotated toincrease the gap height to the next larger insert value to ensure themeasured loading falls within the predetermined range and thedifferential loading falls within a predetermined range (after the softtissue release).

The loading and balance of an implanted joint should be maintainedwithin the predetermined values throughout the range of motion. In atleast one exemplary embodiment, measurements are taken when the tibia isat a ninety-degree angle to the femur. Handle 5612 is used to positionthe spacer block portion of distractor 5600 between the femur and thetibia. The inferior surface 5706 of dynamic distractor 5600 is incontact with the prepared surface of the tibia. In one embodiment, thesuperior surface 5602 is in contact with the remaining portion of thecondyles of the femur. Thus, the condyle surfaces of the femur are incontact with sensors 5608 and 5610 on the superior surface of dynamicdistractor 5600. In this example, a gap height of dynamic distractor5600 is reduced to accommodate the condyles that remain on the distalend of the femur in flexion. The gap height of dynamic distractor 5600can then be adjusted to a height corresponding to the gap height inextension less the thickness of the femoral implant, whereby the leg inflexion is similar to the leg in extension. This can be achieved byspecific ligament releases in flexion and/or rotation of the femoralimplant to achieve a parallel levels between the posterior femoralcondyles and proximal tibia. A femoral sizer can be attached to thedistractor to allow sizing of the femur, coupled with rotation of thefemur. This allows dynamic rotation to obtain equally balanced flexioncompartments.

The loading on sensors 5608 and 5610 with the leg in flexion can bemeasured. The measurement is of value if the condyles are not damaged ordegraded. In one exemplary embodiment, soft tissue release is used toadjust the balance between compartments with the leg in flexion. Thesoft tissue release can also be performed later in the procedure afterthe femoral implant has been implanted. Similar to the leg in extension,soft tissue release is performed to reduce the tension on the sidehaving the higher compartment reading with dynamic distractor 5600 inplace. After soft tissue release, the readings in each compartmentshould be within a predetermined differential range. The distal end ofthe femur can then be prepared for receiving the femoral implant, whichremoves the remaining portion of the condyles. As disclosed, the surfaceof the femur is prepared to be parallel to the prepared tibial surfacein flexion.

In a non-limiting example, the femoral implant component can betemporarily attached to the distal end of the femur. Measurements can betaken throughout the entire three-dimensional range of motion usingdynamic distractor 5600 to ensure that the implanted knee operatessimilarly in all positions. A gap provided by dynamic distractor 5600would be adjusted to a combined thickness of the final insert thicknessand the tibial implant thickness. Dynamic distractor 5600 canincrementally increase or decrease the gap to allow the surgeon todetermine how different insert thicknesses affect load and balancemeasurements. In one exemplary embodiment, accelerometers are used toprovide position and relational positioning information. The data can bestored in memory for later use or displayed to provide instant feedbackto the surgeon on the implant status. Further adjustments to load andbalance can be made with dynamic distractor in place if desired overdifferent positions within the range of motion. Although one implantsequence is disclosed, it is well known that surgeons have differentapproaches, methodologies, and procedure sequences. The use of dynamicdistractor 5600 would be applied similarly to distract and measure indifferent relational positions with the device in place. Furthermore,the device can be used or modified for use on different parts of theanatomy of the muscular-skeletal system.

FIG. 57 shows the dynamic distractor 5600 having a minimum height inaccordance with an exemplary embodiment. Dynamic distractor comprises anupper support structure 5702 having superior surface 5602 and a lowersupport structure 5704 having an inferior surface 5706. In the example,upper support structure 5702, the lift mechanism 5802, and lower supportstructure 5704 supports loading typical for a joint of themuscular-skeletal system. Upper and lower support structures 5702 and5704 comprise rigid and load bearing materials such as metals, compositematerials, and plastics that will not flex under loading. In oneexemplary embodiment, stainless steel is used in the manufacture of thelift mechanism 5802 and upper and lower support structures 5702 and5704.

Dynamic distractor 5600 is used to distract surfaces of themuscular-skeletal system. Dynamic distractor 5600 can be used in aninvasive procedure such as orthopedic surgery. In the non-limitingexample, dynamic distractor 5600 can distract surfaces of themuscular-skeletal system in a range of approximately 8 millimeters toapproximately 25 millimeters. The support surfaces of dynamic distractor5600 do not flex under loading of the muscular-skeletal system. In oneexemplary embodiment, dynamic distractor 5600 has a minimum height orthickness between support surfaces of less than 8 millimeters. In atleast one application, a space between support structures 5702 and 5704is provided when dynamic distractor 5600 is opened to a height greaterthan the minimum height. The space between support structures 5702 and5704 when opened allows a surgeon to perform soft tissue release withthe device in place.

One cavity 5604 is illustrated in superior surface 5602 of upper supportstructure 5702. The cavity 5604 is shaped similarly to a housing 5710 ofsensor 5608. Housing 5710 is placed within cavity 5604 for measuring acompressive force applied across superior surface 5602 and inferiorsurface 5706. In the knee example, a condyle (implanted or natural)couples to an exposed surface of sensor 5608. A pressure or forceapplied to sensor 5608 is measured and displayed by dynamic distractor5600. Sensor 5610 is shown placed in its corresponding cavity 5606 insuperior surface 5602. In one embodiment, the exposed surfaces ofsensors 5608 and 5610 are approximately planar to the superior surface5602. The exposed surface of sensor 5608 and 5610 can be flat orcontoured. Sensors 5608 and 5610 can be removed from upper supportstructure 5702 and disposed after the surgery has been performed. In oneexemplary removal embodiment, a push rod is exposed in the interiorsurface of upper support structure 5702 that, when pressed, can apply aforce to housing 5710 that removes sensor 5608 from cavity 5604.

In one exemplary embodiment, housing 5710 is formed of a plasticmaterial. The sensor and electronic circuitry is fitted in housing 5710.The electronic circuitry comprises any combination of one or moresensors 5720, one or more accelerometers 5722, an ASIC integratedcircuit 5724, a power source 5726, power management circuitry 5728, GPScircuitry 5730, and telemetry 5732. The power source 5726 can be abattery or other temporary power source that is coupled to theelectronic circuitry prior to surgery. The power source 5726 hassufficient power to enable the circuitry for a period of time that willcover the vast majority of surgeries. The power management circuitry5728 works in conjunction with the power source to maximize the life ofthe power source by disabling system components when they are not beingused. In general, an ASIC circuit controls and coordinates when sensingoccurs, can store data to memory (e.g., non-volatile), and can transmitdata in real time or collect and send data at a more appropriate time toa remote system for further processing. The ASIC includes multiple portsthat couple to one or more sensors 5720. The ASIC couples to at leastone of the following: at least one sensor 5720; at least oneaccelerometer 5722; a GPS 5730; and telemetry circuitry 5732. The ASIC5724 can include the integration of telemetry circuitry 5732, powermanagement circuitry 5728, GPS circuitry 5730, memory, and sensors 5720to further reduce the form factor of the sensing system. In the example,the at least one sensor 5720 is a pressure sensor that is coupled to theexposed surface of the housing. The pressure sensor converts thepressure to an electrical signal that is received by the ASIC. The atleast one accelerometer 5722 and GPS 5730 provide positioninginformation at the time of sensing. Telemetry circuitry 5732communicates through a wired or wireless path. In one exemplaryembodiment, the data is sent to a remote processing unit that canprocess and display information for use by the surgeon or medical staff.One or more displays 5734 can be placed on dynamic distractor 5600 tosimplify viewing of any measurement by sensors 5608 and 5610 (e.g.,pressure or force) thereby allowing real time loading and balancedifferential to be seen at a glance. The information can be stored inmemory on the sensor or transmitted to a database for long-term storageand processing.

In a zero gap or minimum height condition, the lift mechanism 5802 isenclosed within the device. An opening 5712 exposes a lift controlmechanism 5716 (e.g., a threaded rod) that is a component of the liftmechanism 5802. The exposed end portion of lift control mechanism 5716is shaped for receiving handle 5612. For example, a proximal end 5714 ofhandle 5612 has a hexagonal shaped opening that operatively couples to ahexagonal shaped end of lift control mechanism 5716. The surfaces of thehexagonal surface mate with the surfaces of the proximal end 5714 ofhandle 5612 for distributing the torque required to rotate the liftcontrol mechanism 5716 when increasing a gap between superior surface5602 and inferior surface 5706 to distract surfaces of themuscular-skeletal system. Distributing the torque over a large surfacearea prevents stripping of either the hexagonal shaped opening of handle5612 or the hexagonal shaped exposed end of lift control mechanism 5716when the device is under load. In one exemplary embodiment, a releaseand locking mechanism fastens handle 5612 to the lift control mechanism5716. Pressing or sliding unlocking button 5618 releases the lockingmechanism to allow removal of handle 5612.

FIG. 58 is a view of dynamic distractor 5600 opened for distracting twosurfaces of the muscular-skeletal system in accordance with an exemplaryembodiment. The lift mechanism 5802 comprises in this example a scissormechanism 5804 for raising and lowering upper support structure 5702with respect to lower support structure 5704. In one exemplaryembodiment, scissor mechanism 5804 comprises more than one supportstructure each having a pivot. Scissor mechanism 3804 is operativelycoupled to an interior surface of upper support structure 5702 and aninterior surface of lower support structure 5704. The structural beamsare pinned to allow pivoting around the axis of attachment. Theremaining beam-ends rest on the interior surfaces of either the upperand lower support structures 5702 and 5704. The beam-ends not fastenedto the interior surfaces support upper and lower support structures 5702and 5704 under load. Threaded rod 5716 is operatively coupled betweenthe beam-ends of scissor mechanism 5804 corresponding to lower supportstructure 5704. Rotating rod 5716 can increase or decrease distancebetween beam ends of the scissor mechanism 5804.

A rod 5806 can be coupled to opening 5614 of handle 5612. The rod 5806can be used to reduce torque needed to rotate threaded rod 5716 ineither direction under load. Increasing a distance between beam-ends ofscissor mechanism 5804 reduces the gap between superior surface 5602 andinferior surface 5706 as the two or more beams pivot around a centrallylocated axis. Conversely, decreasing a distance between beam-ends ofscissor mechanism 5804 increases the gap between superior surface 5602and inferior surface 5706.

FIG. 59 is an anterior view of a dynamic distractor 5600 placed in aknee joint in accordance with an exemplary embodiment. In thenon-limiting example, a distal end 5910 of a femur 5902 is shown havinga femoral implant. The femoral implant has artificial condyles thatcontact sensors 5608 and 5610. The proximal end of a tibia 5904 has beeninitially shaped for receiving a tibial implant. As is well known by oneskilled in the art, a complete knee implant comprises the tibialimplant, the femoral implant, and an insert that includes bearingsurfaces that mate with the artificial condyle surfaces of the femoralimplant. In one exemplary embodiment, dynamic distractor 5600 includesan adjustable handle 5612 that aids in the insertion of the spacerportion into a joint region of the muscular-skeletal system. Forexample, the spacer portion of dynamic distractor 5600 is inserted intothe knee joint using handle 5612 but then is rotated away from thepatellar tendon, collapsed into the trail, or removed to allow thereduction of the patella to depict loads on the instrument. Thethickness or height of the three components is contemplated for the bonesurface preparation when using dynamic distractor 5600. In one exemplaryembodiment, the combined thickness of the femoral implant, final insert,and tibial implant is approximately 20 millimeters thick. Adjustments tothe prepared bone surfaces and thickness of the insert are made duringsurgery using data provided by dynamic distractor 5600 to ensure correctloading, balance, and alignment.

Sensors 5608 and 3610 include circuitry for communication with aprocessing unit 5906. In one embodiment, data is sent wirelessly using aradio frequency communication standard such as Bluetooth, UWB, orZigbee. The data can be encrypted to securely transmit the patientinformation and maintain patient privacy. In one exemplary embodiment,external processing unit 5906 is in a notebook computer, a personalcomputer, or custom equipment. For illustration purposes, externalprocessing unit 5906 is shown in a notebook computer that includessoftware and a GUI designed for the surgical application. The notebookcomputer has a display 5908 that can be used by the medical staff duringthe operation to display real time measurement from dynamic distractor5600. The notebook computer is typically placed outside the surgicalzone but within viewing range of the surgeon.

A substantial benefit of dynamic distractor 5600 is in performing softtissue release both in extension and in flexion. In extension, dynamicdistractor 5600 can be set to a height corresponding to an insert size.In one embodiment, manufacturers of an implantable joint will providespecifications for load, balance, and alignment once sufficient clinicaldata has been generated. The surgeon can also manipulate the patient'sleg to subjectively gauge the loading on the joint. The surgeon canadjust dynamic distractor 5600 to increase or decrease the height or gapcorresponding to a different thickness insert size until a desiredloading is achieved. A substantial imbalance corresponds to adifferential loading measured by sensors 5608 and 5610 outside apredetermined range. The loading measured by sensors 5608 and 5610should be approximately equal in each compartment. The data provided bysensors 5608 and 5610 can be used to provide a solution to the surgeon.For example, data from sensors 5608 and 5610 is sent wirelessly toprocessing unit 5906. The data indicates a substantial differentialpressure between measurements from sensors 5608 and 5610 (i.e.,imbalance). In one embodiment, the data can be processed and displayedon display 5908 with suggestions for the removal of material from thetibial surface to reduce the differential reading. The suggestion caninclude where material should be removed and how much material isremoved from the tibial surface. Alternatively, the assessment of theloading and differential between compartments can indicate that softtissue release is sufficient to bring the joint within predeterminedranges for absolute load and balance.

A further benefit of dynamic distractor 5600 is in soft tissue releaseto modify loading measured by sensors 5608 and 5610 and the differential(i.e., balance) between the measured values in each compartment. Dynamicdistractor 5600 remains in place while soft tissue release is beingperformed allowing for real time measurement and modification to occur.The feedback to the surgeon is immediate as the soft tissue cuts aremade. Two issues are resolved by dynamic distractor 5600. An open areaformed between the interior surfaces of upper support structure 5702 andlower support structure 5704 under distraction provides surgical access.In most cases, the gap is sufficient to allow a scalpel or blade accessto the lateral or medial ligaments for soft tissue release in the gap orperipheral to dynamic distractor 5600. In general, soft tissue releaserequires anterior access to the joint space. Handle 5612 of dynamicdistractor 5600 can be removed providing further anterior access to thejoint. Alternatively, handle 5612 is hinged or includes a joint allowingit to be positioned away from the surgical area. Thus, dynamicdistractor 5600 enables soft tissue release by the surgeon to adjust theabsolute loading measured by sensors 5608 and 5610 in each compartmentto be within a predetermined range and to adjust the difference incompartment loadings within a predetermined range without removing thedevice.

FIG. 60 is a lateral view of dynamic distractor 5600 in a knee jointpositioned in flexion in accordance with an exemplary embodiment. In anon-limiting example, load and balance measurements are performed usingdynamic distractor 5600 with the leg in at least two positions (e.g.,the leg in extension and the leg in flexion). For example, measurementsare taken in extension as disclosed hereinabove and in flexion with theleg positioned having femur 5902 forming a ninety-degree angle to tibia5904. In one embodiment, accelerometers in sensors 5608 and 5610 areused to determine relative positioning of the femur and tibia to oneanother. Under user control, measurements are taken at several pointsover the range of motion with dynamic distractor 5600 in place, therebysubstantially simplifying a data collection process. Measurements overthe range of motion can be taken when the femoral implant has beeninstalled or if the distal femur has not been modified. Alternatively,dynamic distractor 5600 can be reduced in height by rotating handle 5612until there is sufficient room to move the leg to a new position andthen increasing the height of distractor 5600 to create the appropriategap.

Another beneficial feature of opening 5614 of handle 5612 is the abilityto place drop alignment rod 6002 therethrough. Drop alignment rod 6002is a visual aid for the surgeon and is used to ensure that the leg isaligned adequately when the load and balance measurements are taken.Drop alignment rod 6002 is used in conjunction with knowledge of the legmechanical axis or with markers placed on the patient to checkalignment. The surgeon aligns alignment rod 6002 to the leg mechanicalaxis and makes a subjective determination that the leg is correctlypositioned. The surgeon can increase accuracy by pre-identifying pointson the mechanical axis. The surgeon has the option of making adjustmentsif drop alignment rod 6002 indicates a potential positional error. Dropalignment rod 6002 can be tapered having a section with a greater widththan opening 5614 to retain it in place and prevent it from fallingthrough the opening 5614. Other embodiments to retain drop alignment rod6002 can also be used.

Alternatively, drop alignment rod 6002 can be a smart alignment aid forthe surgeon that incorporates electronics similar to that described inFIG. 2. In general, drop alignment rod includes sensors to allowdepiction of the mechanical axis. For example, drop alignment rod 6002can incorporate sensors to identify position in three-dimensional space.The electronics allow drop alignment rod 6002 to communicate withpre-operative defined locations or locations that are identified at thetime of surgery using locator electronics. The drop rod can house lightemitters to depict an axis as will be discussed in more detailhereinbelow. The electronics can include communication to externalprocessing unit 5906 with a graphic user interface that has themechanical axis loaded therein.

FIG. 61 is a lateral view of a dynamic distractor 5600 in a knee jointcoupled to a cutting block 6102 in accordance with an exemplaryembodiment. In general, the surgeon utilizes surgical tools to obtainappropriate bony cuts to the skeletal system. The surgical tools areoften mechanical devices used to achieve gross alignment of the skeletalsystem prior to or during an implant surgery. In the knee example,mechanical alignment aids are often used during orthopedic surgery tocheck alignment of the bony cuts of the femur and tibia to themechanical axis of the leg. The mechanical alignment aids are notintegrated together, take time to deploy, and have limited accuracy.Dynamic distractor 5600 in concert with cutting block 6102 is anintegrated system for achieving alignment that can greatly reduce set uptime thereby minimizing stress on the patient.

As illustrated, the leg is in flexion having a relational position of 90degrees between femur 5902 and tibia 5904. A femoral rod 6108 is coupledthrough the intermedullary canal of femur 5902. A cutting block 6102 isattached to the femoral rod 6108 for shaping a portion of the surface ofthe distal end of femur 5902 for receiving a femoral implant. Kneereplacement surgery entails cutting bone a certain thickness andimplanting a prosthesis to allow pain relief and motion. During thesurgery, instruments are used to assist the surgeon in performing thesurgical steps appropriately. Dynamic distractor 5600 aids the surgeonby allowing quantitative measurement of the gap and parametermeasurement during all stages of the procedure. For the knee, the datacan supplement a surgeon's “feel” by providing data on absolute loadingin each compartment, the load differential between compartments,positional information, and alignment information.

The portion of the surface of the distal end of femur 5902 in contactwith dynamic distractor 5600 is shaped in a subsequent step. In anon-limiting example, the portion of the condyles in contact withsuperior surface 5602, sensor 5608, and sensor 5610 are the naturalcondyles of the femur. The portion of the distal end of femur 5902 beingshaped corresponds to the condyle portion that would be in contact withthe final spacer while the leg is in extension and partially through therange of motion. In at least one exemplary embodiment, an uprod 6104 ofdynamic distractor 5600 couples to cutting block 6102. Uprod 6104 aidsin the alignment of the cutting block 6102 to dynamic distractor 5600and tibia 5904. Uprod 6104 further stabilizes cutting block 6102 toprevent movement as the distal end of femur 5902 is shaped.

In one exemplary embodiment, handle 5612 is removed and an uprod 6104 isattached to threaded rod 5716. The uprod 6104 can include a hinge thatpositions rod 6104 vertically to mate with cutting block 6102.Alternatively, handle 5612 can include a hinge. In this example, handle5612 is uprod 6104 and is inserted into cutting block 6102. Furthermore,uprod 6104 can be fastened or coupled to an opening or feature in handle5612 to couple to cutting block 6102. In general, uprod 6104 is placedat a right angle to the inferior surface of lower support structure 5704of dynamic distractor 5600. In a prior step, the leg alignment can bechecked to ensure it is within a predetermined range of the mechanicalaxis. In one exemplary embodiment, uprod 6104 aligns approximately tothe mechanical axis to secure cutting block 6102 in an appropriategeometric orientation. Cutting block 6102 includes a channel 6106 forreceiving uprod 6104. Uprod 6104 can be adjustable in length to simplifyinsertion. As previously mentioned, uprod 6104 is attached to dynamicdistractor 5600 to align with the mechanical axis of the legcorresponding to tibia 5904. Fitted in the opening and into channel6106, uprod 6104 maintains a positional relationship between cuttingblock 6102, dynamic distractor 5600, femur 5902, and tibia 5904. Morespecifically, the proximal surface of tibia 5904 is aligned to themechanical axis thereby fixing the position of femur 5902 and cuttingblock 6102 in a similar fixed geometric relational position. Thus, thedistal end of femur 5902 is cut having surfaces parallel to the proximaltibial surface by coupling dynamic distractor 5600 to cutting block 6102through uprod 6104.

FIG. 62 is an anterior view of a cutting block 6102 coupled to dynamicdistractor 5600 in accordance with an exemplary embodiment. Cuttingblock 6102 is attached to the distal end of femur 5902. Femoral rod 6108extends through cutting block 6102 into the intermedullary canal. Uprod6104 is shown extending vertically into channel 6106 of cutting block6102. In combination, femoral rod 6108 and uprod 6104 prevent movementand maintain alignment of the cutting block to the leg mechanical axis.As shown, cutting block 6102 is illustrated as rectangular in shape.Cutting block 6102 is shaped to form a predetermined bone shape on thedistal end of femur 5902 for receiving a femoral implant. Thus, theshape of cutting block 6102 can vary significantly from that showndepending on the implant. The size of the cutting block 6102 correspondsto the distal end size and the femoral implant selected by the surgeon.The surgeon uses a bone saw to remove portions of the distal end offemur 5902 in conjunction with cutting block 6102. In general, thecutting block 6102 acts as a template to guide the bone saw and to cutthe distal end of the femur in a predetermined geometric shape. Asdisclosed previously in the example, the portion of the distal end offemur 5902 that is shaped corresponds to the contact portion of thecondyles when the leg is in full extension and partially in flexion(i.e., <90 degrees). As mentioned previously, the portion of the distalend of femur 5902 in contact with the superior surface 5602 of dynamicdistractor 5600 is shaped in a subsequent step.

FIG. 63 is an illustration of dynamic distractor 5600 includingalignment in accordance with an exemplary embodiment. Dynamic distractor5600 includes one or more recesses 6302 in a handle 6304 for receivingan alignment aid to align a leg along the mechanical axis. In oneembodiment, handle 6304 can be handle 5612 that includes recesses 6302.Alternatively, handle 6304 is a separate handle for dynamic distractor5600. Prior to checking alignment, handle 5612 is removed from dynamicdistractor 5600. Handle 6304 is then coupled to threaded rod 5716 forraising and lowering the support structures.

Initial bony cuts are made in alignment with the mechanical axis of theleg. In the knee example, the alignment aid is used to check that thefemur and the tibia are correctly oriented prior to cutting. Thesurfaces of the bones are cut in alignment to the mechanical axis usinga jig. Thus, the cut surfaces on the distal end of the femur and theproximal end of the tibia are aligned and can be used as a referencesurfaces during the procedure. Alternatively, the alignment aid can beused to verify alignment throughout the procedure. Recesses 6302 can bethru-holes in handle 6304. In a non-limiting example, the alignment aidis one or more lasers 6308. Laser 6308 is/are used to point along themechanical axis of the leg. In one exemplary embodiment, lasers 6308 areused to check alignment of the leg. A first laser is used to point inthe direction of the hip joint. A second laser is used to point towardsthe ankle. In one embodiment, the first and second lasers are integratedinto a single body. Handle 6304 further comprises a hinge 806 to changethe angle at which lasers 6308 are directed. The housing of lasers 6308includes a power source such as a battery to generate the monochromaticlight beam. The housing fits within one of recesses 6302 or a thru-hole.Lasers 6308 can be a disposable item that is discarded after the surgeryis completed.

FIG. 64 is a side view of a leg in extension with dynamic distractor5600 in the knee joint region in accordance with an exemplaryembodiment. The mechanical axis of the leg is approximately a straightline from the center of the femoral head through the knee joint andextending to the middle of the ankle joint. In a correctly aligned kneejoint, the mechanical axis will pass approximately through the center ofthe knee joint. Alignment can be checked when dynamic distractor 5600 ispositioned in the knee joint region. As illustrated, the leg is inextension with handle 6304 extending vertically from the knee jointregion. In one embodiment, a target 6402 is placed in an ankle or toeregion of the foot in a path corresponding to center of the ankle on themechanical axis of the leg. Similarly, a target 6404 is placed in a pathcorresponding to the center of the head of the femur on the mechanicalaxis of the leg. Targets 6402 are placed at a height similar to that oflasers 6308. Lasers 6308 are installed in the handle with one pointingin the direction of the hip joint and another pointing in the directionof the ankle joint. From the top view, lasers 6308 send out a beam oflight from a position that corresponds to the center of the knee. In oneembodiment, the direction of the beam from lasers 6308 is directedperpendicular to a plane of the prepared surface of the proximal end ofthe tibia.

Lasers 6308 are directed perpendicular to the inferior surface ofdynamic distractor 5600. The placement of dynamic distractor 5600 on theprepared tibial surface is such that handle 6304 extends vertically at apoint corresponding to the center of the knee joint. The leg is alignedcorrectly when the beams from lasers 6308 hit the target at the pointscorresponding to the center of the head of the femur and the center ofthe ankle. Lasers 6308 are positioned to align with the center of theknee joint. The surgeon can make adjustments to the bone surfaces orutilize soft tissue release to achieve alignment with the leg mechanicalaxis when lasers 6308 are misaligned to the target. The system can beused to give a subjective or a measured determination on leg alignmentin relation to a valgus or valgus alignment. The direction ofmisalignment in viewing targets 6402 and 6404 will dictate the type ofcorrection and how much correction needs to be made. In an alternateexemplary embodiment, lasers 6308 can be aimed such that the beam isviewable along the leg in a region by the center of the femoral head andthe center of the angle. The surgeon can use this as a subjective visualgauge to determine if the leg is in alignment to the mechanical axis andrespond appropriately, depending on what is viewed.

FIG. 65 is a front view of a leg in extension with dynamic distractor5600 in the knee joint area in accordance with an exemplary embodiment.Dynamic distractor 5600 can measure spacing between the distal end ofthe femur and the tibia, loading in each compartment, and differentialloading between compartments. The data can be sent to a processing unitand display as disclosed hereinabove. As mentioned previously, themechanical axis of the leg corresponds to a straight line from thecenter of the ankle, through the center of the knee, and the center ofthe femoral head. Targets 6402 and 6404 are respectively locatedoverlying the mechanical axis in an area local to the ankle and the hipregions. Targets 6402 and 6404 can include a fixture such as a strap,brace, or jig to hold the targets temporarily along the mechanical axis.Lasers 6308 are enabled and placed in handle 6304. FIG. 65 illustratesthat targets 6402 and 6404 are on approximately the same plane as beamsemitted by lasers 6308 such that the beams impinge on a target unlessgrossly misaligned. Targets 6402 and 6404 can include calibrationmarkings to indicate a measure of the misalignment. Alternatively,handle 6304 is hinged allowing adjustment of the angle at which the beamfrom lasers 6308 is directed. The direction of the lasers 6308corresponds to the plane of the bone cuts for the implant and thebalance of the joint. Thus, the surgeon using a single device has bothquantitative and subjective data relating to alignment to the mechanicalaxis, loading, balance, leg position, and gap measurement that allowsgross/fine tuning during surgery that results in more consistentorthopedic outcomes.

FIG. 66 is an illustration of a system or kit 6600 for measuring one ormore parameters of a biological life form in accordance with anexemplary embodiment. In a non-limiting example, the system providesreal time measurement capability to a surgeon of one or more parametersneeded to assess a muscular-skeletal system. System 6600 comprises aplurality of spacer blocks 6602, a distractor 6604, sensors 6606,targets 6610, lasers 6614, a charger 6616, a receiver 6618, a reader6620, a processing unit 6622, a display 6624, a drop rod, an uprod, acutting block, a handle 6632, and a dynamic data repository and registry6636. The system is adaptable to provide accurate measurements ofparameters such as distance, weight, strain, pressure, wear, vibration,viscosity, and density to name but a few. In one exemplary embodiment,system 6600 is used in orthopedic surgery and more specifically toprovide intra-operative measurement during joint implant surgery. System6600 is adapted for orthopedic surgery and more specifically for kneesurgery to illustrate operation of the system.

In general, system 6600 provides alignment and parameter measurementsystem for providing quantitative measurement of the muscular-skeletalsystem. In one exemplary embodiment, system 6600 is integrated withtools commonly used in orthopedics to reduce an adoption cycle toutilize new technology. System 6600 replaces standalone equipment ordedicated equipment that is used only for a small number of proceduresthat justifies the extra time and set up required to use this type ofequipment. Furthermore, it is well known, that dedicated equipment cancost hundreds of thousands or millions of dollars for a single device.Many hospitals and other healthcare facilities cannot afford the highcapital cost of these types of systems. Moreover, specialized equipmentsuch as robotic systems or alignment systems for orthopedic surgerytypically has a large footprint. The large footprint creates space andcost issues. The equipment must be stored, set up, calibrated, placed inthe operating room, and then removed.

Conversely, measurement and alignment components of system 6600 are lowcost disposables that make the measurement technology more accessible tothe general public. There is no significant capital investment requiredto use the system. Moreover, payback begins immediately with use inproviding quantitative information related to procedures therebyallowing analysis of outcomes based how the parameters being measuredaffect the procedure being measured. The data is used to initiatepredetermined specifications for the procedure that can be measured andadjusted during the course of the procedure thereby optimizing theoutcomes and reducing revisions. As mentioned previously, system 6600can be used or integrated with tools that the majority of orthopedicsurgeons have substantial experience or familiarity using on a regularbasis. In one exemplary embodiment, sensors 6606 are placed in a spacerthat separates two surfaces of the muscular-skeletal system. In anon-limiting example, the spacer can be spacer blocks 6602 or distractor6604. A measurement of the parameter is taken after the spacer isinserted between at least two surfaces of the muscular-skeletal system.Sensors 6606 are in communication with processing unit 6622. In oneembodiment, the processing unit 6622 is outside the sterile field andincludes display 6624 and a GUI to provide the data in real time to thesurgeon. Thus, the learning cycle can be very short to provide real timequantitative feedback to the surgeon as well as storing the data forsubsequent use.

In a non-limiting example, a spacer separates two surfaces of themuscular-skeletal system. The spacer has an inferior surface and asuperior surface that contact the two surfaces. The spacer can have afixed height or can have a variable height. The fixed height spacer isknown as spacer blocks 6602. Each spacer block 6602 has a differentthickness. The variable height spacer is known as the distractor 6604.The surface area of spacer blocks 6602 and distractor 6604 that coupleto the surfaces of the muscular-skeletal system can also be provided indifferent sizes. The handle 6632 extends from the spacer and typicallyresides outside or beyond the two surface regions. The handle 6632 isused to direct the spacer between the two surfaces. In one exemplaryembodiment, the handle 6632 operatively couples to a lift mechanism ofthe distractor 6604 to increase and decrease a gap between the superiorand inferior surfaces of the spacer. The spacer and handle 6632 is partof system 6600 to measure alignment of the muscular-skeletal system. Inone exemplary embodiment, at least one of the surfaces of themuscular-skeletal system that contacts the spacer has an optimalalignment to a mechanical axis of the muscular-skeletal system. Thesystem measures the surface to mechanical axis alignment. In anon-limiting example, the misalignment can be corrected by a surgeonwhen the surface is misaligned to the mechanical axis outside apredetermined range as disclosed below.

Knee replacement surgery entails cutting bone having a predeterminedspacing and implanting a prosthesis to allow pain relief and motion.During the surgery, instruments are used to assist the surgeon inperforming the surgical steps appropriately. The majority of surgeonscontinue to use passive spacers to aid in defining the gaps between thecut bones. The thickness of the final insert is selected after placingone or more trial inserts in the artificial joint implant. Thedetermination of whether the implanted components are correctlyinstalled is still to a large extent by the “feel” of the surgeonthrough movement of the leg. In general, spacer blocks 6602 anddistractor 6604 of system 6600 is a spacer having an inferior andsuperior surface that separate at least two surfaces of themuscular-skeletal system. In the knee example, the inferior and superiorsurfaces are inserted between the femur and tibia of the knee. At leastone of the inferior or superior surfaces of spacer blocks 6602 anddistractor 6604 have a cavity or recess for receiving sensors 6606. Inone exemplary embodiment, the cavity is on the superior surface ofspacer blocks 6602 and distractor 6604. A gap between the surfaces ofdistractor 6604 is adjustable as described hereinabove. Tray 6608includes multiple spacer blocks 6602 each having a different thickness.Thus, spacer blocks 6602 and distractor 6604 provide the surgeon withmore than one option to measure spacing, alignment, and loading duringthe procedure. A benefit of the system is the familiarity that thesurgeon will have with using similar type devices, thereby reducing thelearning curve to utilize system 6600. Furthermore, system 6600 cancomprise spacer blocks 6602 and distractor 6604 having spacer blockshaving different sized superior and inferior surface areas to morereadily accommodate different bone shapes and sizes.

In general, a rectangle is formed by the bony cuts during surgery. Theimaginary rectangle is formed between the cut distal end of a femur andthe cut proximal end of tibia in extension and in conjunction with themechanical axis of the lower leg. The prepared surfaces of the femur andtibia are shaped to respectively receive a femoral implant and a tibialimplant. The femoral and tibial surfaces are parallel to one anotherwhen the leg is in extension and in flexion at ninety degrees. Apredetermined width of the rectangle is the spacing between the planarsurface cuts on femur and tibia. The predetermined width corresponds tothe thickness of the combined orthopedic implant device comprising thefemoral implant, an insert, and the tibial implant. A target thicknessfor the initial cuts is typically on the order of twenty millimeters.The insert is inserted between the installed femoral implant and thetibial implant. In a full knee implant, the insert has two bearingsurfaces that are shaped to receive the condyle surfaces of the femoralimplant.

In at least one exemplary embodiment, when inserted into the spacerblocks 6602 and/or distractor 6604, sensors 6606 can measure load andposition. While it may be beneficial for the sensors 6606 to be chargedwhen first use, alternatively, sensors 6606 are placed in a charger 6616prior to the implant surgery being performed. Charger 6616 provides acharge to an internal power source within sensors 6606 that will sustainsensor measurement and data transmission throughout the surgery. Charger6616 can fully charge sensor 6606 or be used as a precautionary measureto insure the temporary power storage is holding sufficient charge.Charger 6616 can charge the sensors 6606 via a wireless connectionthrough a sterilized packaging. Sensors 6606 are in communication withprocessing unit 6622. Sensors 6606 include a transmitter for sendingdata. Processing unit 6622 can be logic circuitry, a digital signalprocessor, microcontroller, microprocessor, or part of a system havingcomputing capability. As shown, processing unit 6622 is a notebookcomputer having a display 6624. The communication between sensors 6606and processing unit 6622 can be wired or wireless. In one embodiment,receiver 6618 is coupled to the processing unit 6622 for wirelesscommunication. A carrier signal for data transmitted from sensors 6606can be radio frequency, infrared, optical, acoustic, and microwave toname but a few. In a non-limiting example, receiver 6618 receives datavia a radio frequency signal in a short range unlicensed band sufficientfor transmission within the size of an operating room. Information fromprocessing unit 6622 can be sent through the Internet 6634 to a dynamicdata repository and registry 6636 for long-term storage. The dynamicdata repository and registry 6636 will be discussed in greater detailhereinbelow. In one exemplary embodiment, the data is stored in a serveror as part of a larger database.

The surgeon uses system 6600 to aid in the preparation of bone surfaces,to measure loading, to measure balance, to check alignment, and to tunethe knee joint prior to a final insert being installed. A reader 6620 isused to scan in information prior to or during the surgery. In oneexemplary embodiment, the reader 6620 can be wired or wirelessly coupledto the processing unit 6622. Processing unit 6622 can process theinformation, display it on display 6624 for use during a procedure, andstore it in memory and/or a database for long-term use. For example,information on components used in the surgery such as the artificialknee components or components of system 6600 can be converted to anelectronic digital form using reader 6620 during the procedure.Similarly, patient information or procedural information can also bescanned in, input manually, or captured by other measures to processingunit 6622.

The leg is placed in extension and the knee joint is exposed byincision. In one exemplary embodiment, the surgeon prepares the proximalend of the tibia. The prepared tibial surface is typically at a90-degree angle to the mechanical axis of the leg. Targets 6610 areplaced overlying the mechanical axis near the ankle and hip joint. Thesurgeon can select one of the spacer blocks 6602 or dynamic distractor6604 for insertion in the joint region. The selected spacer block has apredetermined thickness that is imprinted on the spacer block or can bedisplayed on display 6624 by scanning the information. Alternatively,distractor 6604 is distracted by the surgeon within the joint region.The amount of distraction can be read off of distractor 6604 or can bedisplayed on display 6624.

In a non-limiting example of aligning two surfaces of themuscular-skeletal system, alignment of the leg to the mechanical axis ismeasured and/or a subjective check can be performed by the surgeon usingan alignment aid. At least one component of the alignment aid isdisposable. The alignment aid comprises lasers 6614 connectable to ahandle 6612 of the selected spacer block or a handle 6632 of distractor6604 with the leg in extension. The alignment aid further includestargets 6610. Targets 6610, lasers 6614, or both can be disposable.Accelerometers in sensors 6606 provide positional information of thetibia in relation to the femur. For example, display 6624 will indicatethat the angle between the tibia and femur is 180 degrees when the legis in extension. The beam from lasers 6614 hit targets 6610 and providesa measurement of the position of the tibia in relation to the femurcompared to the mechanical axis of the leg. In one exemplary embodiment,lasers 6614 are centrally located above the knee joint overlying themechanical axis of the leg. The beam from lasers 6614 is directedperpendicular to the plane of the surface of the tibia. The beam fromlasers 6614 will align and overlie the mechanical axis if the surface ofthe tibia is the perpendicular to the mechanical axis. The beam fromlasers 6614 would hit targets 6610 at a point that indicates alignmentwith the mechanical axis. A valgus or vargus reading can be read wherethe beam hits the calibrated markings of targets 6610 if the leg is notaligned. The surgeon can then make an adjustment to bring the leg intocloser alignment to the mechanical axis if deemed necessary. Jigs orcutting blocks can also be used in conjunction with lasers 6614 andtargets 6610 to check alignment prior to shaping. The jigs or cuttingblocks are used to shape the bone for receiving an implant. The distalend of femur and the proximal end of tibia are shaped for receivingorthopedic joint implants. In a further exemplary embodiment, sensorscan be attached to the cutting jigs or devices to aid the surgeon inoptimizing the depth and angles of their cuts.

As an example, knee replacement surgery can be divided intounicompartmental knee surgery, bicompartmental (Cruciate sparing), andtotal knee replacement surgery. Unicompartmental knee surgery isbeneficial in the appropriate patient to relieve pain from arthritis inone compartment and restore the patient's knee function. Bicompartmentalknee replacement allows retention of the crucuate ligaments whiletreating generalized knee arthritis. Unicompartmental knee surgery hasshown long lasting benefits and an earlier recovery phase than thetraditional total knee replacement. Patient selection is critical. Thepathology must only affect one compartment (most commonly the medialside), the knee deformity must be minimal and passively correctable.Bicompartmental Knee replacements preserve the cruciate ligaments andprovide the added stability of ligament retention for post-operativefunction. The prostheses have been modified over time and the bearingsurfaces have shown the ability to function well into the second decade.

The last parameter to address is the surgical technique. If aunicompartmental or bicompartmental knee is positioned poorly, thecomponents will fail early and will require a revision knee surgery. Ifthe anterior cruciate ligament and the posterior cruciate ligament arenot tensioned correctly along with the medial collateral ligament andthe lateral collateral ligaments in a bicompartmental bicruciate kneereplacement, the knee will not function well and a revision will berequired. Positioning can be divided into several issues:

-   -   1) The femoral component and tibial component must be placed at        the appropriate depth in the bone and must be sized and        positioned correctly on the bone;    -   2) The components must be positioned appropriately to each other        through all ranges of motion; and    -   3) The flexion and extension gaps (soft tissue tension) must be        balanced in order for the knee to function appropriately and to        avoid early bearing wear.

Through pre-op planning (using Xrays, Cat Scans, MRI's etc.), andintra-operative jigs, the correct component-to-component alignment andimplant positioning can be achieved. Recently, Robotic technology hasallowed physicians to precisely prepare the bone at the correct angles,depth, etc. The ability to precisely balance the knee through all rangesof motion has not been mastered, however. While performing aunicompartmental/bicompartmental knee replacement, physicians do notroutinely release collateral ligaments to achieve alignment asphysicians can do in total knee replacements. Also, the anteriorcruciate and posterior cruciate ligaments are required to be present.The most important parameter is the ability to balance the knee inflexion and extension, coupled with correct mechanical leg alignment;this allows physicians to achieve near normal knee kinematics. Thismeans that the amount of bone removed from the tibia and femur allowsequal balance and loads on the prosthesis through all ranges of motion.

The ligaments must be tensioned and loaded appropriately as well. Thepresent way physicians achieve this is through the concepts of replacingwhat is removed. The problem with this is that the physicians haveunequal wear of the extension gap compared to the flexion gap in mostmedial knee arthritis. The anterior part of the knee is worn, while theposterior part of the knee is preserved. The opposite is true in lateralknee arthritis. The most common procedure to achieve correct balance isto cut the tibia first and place a feeler gage in between the femur andtibia and determine the flexion gap. The surgeon then extends the kneeand uses feeler gauges to determine the balance between the femur andtibia in extension (the Extension Gap). The problems encountered withthis present system are that the feeler gages are plastic with no finepressure determination. The surgeon is taught to insert and pull out thefeeler gage or distractor, and get a “feel” of what is right. This isdifficult to perfect if the physician does not perform a large number ofsurgeries and is difficult to teach other surgeons what is a “correct”feel.

The tibia is cut first due to the fact that it will control alignmentand it can affect the flexion and extension gap. The angle of tibiaslope will affect the flexion gap. The amount of posterior femurresected will affect the flexion gap. The extensor gap is usually wornmore in the medial arthritic knee. The amount of resection of theanterior and distal femur will affect the extension gap. The otherconcerns include, when presently changing depth and slope, the physicianaffects the angles of the bone cuts and ultimately how the componentswill load each other and articulate in the patient's knee, as well asthe tension on the crucuate and collateral ligaments.

In one exemplary embodiment, the sensor system according to theinvention allows real time loads on trial inserts, implants, andinstruments during surgery. This gives the surgeon true pressurereadings that help determine the depth, angle and placement of thecomponents. The ability to transmit this information to a “smartinstrument” or a robotic system allows the computer to process theinformation. This is compared to a preset algorithm that enables a smartinstrument to refine the bone cuts to achieve optimal balance of thegaps, while maintaining precise component-to-component alignment. Asmart instrument as referred to herein is any mechanical jig or cuttinginstrument that can receive and integrate information and use thisinformation to enable surgical preparation of a joint. The sensor systemcan, then, be implanted in the final polyethylene insert to determinepost-operative loads, kinematics, abnormal wear, or motion of theimplant.

The sensor system in one exemplary embodiment includes anexciter/receiver that sends a signal to each other. When loads areapplied to the plastic insert, the signal wave is deflected. Thedeflection of the energy wave and the time it takes to resume itsresting state is placed over time and a value is produced. This valuecan be a parameter of load that is sent to a transistor. Nexense sensortechnology described above can be used. Other sensors utilizingultrasound, piezoelectrics, MEMS, fiberoptics, strain gauges, and sensorcomposites such as film can be employed in the system. The informationprovided by the sensors can be sent to a computer screen by wirelesstechnology that is in present use. The surgeon can visually analyze thisinformation. A signal can also be sent to a “smart instrument” that hasa built in algorithm to burr or cut the femur and or tibia in a fashionthat will balance the loads on the implant through all ranges of motionwhile maintaining optimal implant positioning.

FIGS. 87 to 100 are referenced with regard to this exemplary embodimentof the sensor system. FIGS. 87 and 88 illustrate a medial knee implant,which is made of a metal femoral prosthesis and a plastic and/or metaltibial implant. The implant is bonded to the bone. The flexion gap isshown. FIGS. 89 and 90 illustrate the knee implant in extension. Theimplant is shown on the medial side of the knee in black. FIGS. 91 and92 depict the plastic insert that is used to trial the implant. Thetibia is cut and then the tibial trial is used to determine the loadswhen the trial articulates through a range of motion on the naturalfemur. The sensors reside in the trial insert and, as loads are applied,the sensors detect them. FIG. 93 shows the transmission of loadinformation from the trial insert in a wireless fashion. The inserthouses the sensing system and the powering source and transmitter. Thehandle to insert the trial houses the transmitter and powering system.This information is received and processed. The information is then sentto a monitor for visual inspection. The information allows the surgeonto adjust his/her plans. The proposed change in bone cuts will bedepicted in relationship to how it will affect the pre-operativeplanning of implant alignment. Another option exists, wherebyinformation is sent to a “smart instrument”. Such an instrument can be amounted robotic arm or a free instrument. The smart instrument processesthe information and modifies the bone cuts to balance the knee gaps andintegrate the optimal component alignment.

FIG. 94 depicts the knee as it is taken through a range of motion. Thenatural cartilage loads the trial implant. This gives the needed loadparameters to determine the femoral cuts and positioning. FIG. 95 showsthe plastic trial with the embedded sensors. FIG. 96 illustrates the“smart instrument” burring/cutting the appropriate pre-determined amountof cartilage and bone off the femur for optimal femoral implantplacement that achieves optimal component alignment and balanced gaps.

FIGS. 97 and 98 depict the final implant that has been inserted. Thefinal tibial insert has an embedded sensor system that will givepost-operative information to the surgeon regarding any parameter thatis needed. Examples includes load, wear, abnormal motion, etc. FIGS. 99and 100 depict the final tibial insert with the embedded sensors.

This exemplary sensor system describes its use in a medialunicompartmental knee replacement. It can be used in lateral orpatello-femoral implants. It can be used in Total Knee Implants. It canbe used in any other orthopedic implant that is placed in the body toaid in optimal component placement and soft tissue balance of the joint.

Sensors 6606 measure the loading in each compartment for the depth orthickness of the selected spacer block or the distracted gap generatedby distractor 6604. In one exemplary embodiment, the loadingmeasurements are taken after the initial bone cuts are determined to bewithin a predetermined range of alignment with the mechanical axis. Theload measurement in each compartment is either high, within anacceptable predetermined range, or low. A load measurement above apredetermined range can be adjusted by removing bone material, selectinga thinner spacer block, adjusting the gap of distractor 6604, or by softtissue release. In general, the gap between the femur and the tibia atwhich the measurement taken corresponds to a final insert thickness. Inone embodiment, the gap is selected to result in a load measurement onthe high side of the predetermined range to allow for fine-tuningthrough soft tissue release. Conversely, a load measurement below thepredetermined range can be increased using the next thicker spacer blockor by increasing the gap of distractor 6604. Data from sensors 6606 istransmitted to processing unit 6622. Processing unit 6622 processes thedata and displays the information on display 6624 for use by the surgeonto aid in fine-tuning. Display 6624 would further provide positionalinformation of the femur and tibia. The absolute loading in eachcompartment is measured and displayed on display 6624. As is known byone skilled in the art, the gap created by the bone cuts accommodatesthe combined thickness of the femoral implant, the tibial implant, andthe insert. The gap using spacer blocks 6602 or distractor 6604 takesinto account the combined thickness of the implant components. In anon-limiting example, the gap is chosen based on the availability ofdifferent thicknesses of the final insert. Thus, the loading on thefinal or permanent insert placed in the joint will measure within thepredetermined range as prepared by using system 6600.

Balance is a comparison of the load measurement of each condyle surface.In general, balance correction is performed when the measurements exceeda predetermined difference value. Soft tissue balancing is achieved byloosening ligaments on the side of the compartment that measures ahigher loading. In one embodiment, system 6600 allows the surgeon toread the loading measurement for each compartment on one or moredisplays on spacer blocks 6602 or distractor 6604. Another factor isthat the difference in loading can be due to surface preparation of thebony cuts for either femoral implant or the tibial implant. If thedifferential is substantial, the surgeon has the option of removing boneon either surface underlying the implant to reduce the loadingdifference.

In one exemplary embodiment, the absolute load adjustments and balanceadjustments are performed by soft tissue release in response to theassessment of each compartment. Load and balance adjustment is achievedwith the selected spacer block or distractor 6604 in the knee joint.Spacer blocks 6602 and distractor 6604 have a gap to provide peripheralaccess between the superior and inferior surfaces of the device, therebygiving the surgeon access to perform soft tissue release to eithercompartment with real-time load measurement shown on display 6624. In atleast one exemplary embodiment, handles 6612 of spacer blocks 6602 orhandle 6632 of distractor 6604 can be removed or positioned. Handles6612 or handle 6632 can be positioned away from the surgical area orremoved allowing the surgeon access to perform soft tissue release. Thesoft tissue release is performed to each compartment to adjust theabsolute loading within the predetermined range, and further adjustmentcan be performed to reduce the differential loading between thecompartments to within a predetermined differential range. Consequently,the surgical outcome is a function of system 6600 as complemented withthe surgeon's abilities but is not so highly dependent alone on thesurgeon's skill. The device captures the “feel” of how an implanteddevice should properly operate to improve precision and minimizevariation including haptic and visual cues.

A similar process is applied with the lower leg in flexion with tibiaforming a ninety degree angle with the femur. In one exemplaryembodiment, one or more bone cuts are made to the distal end of femurfor receiving the femoral implant. The preparation of the femurcorresponds to the leg in extension. As disclosed above, the selectedspacer block or distractor 6604 can be coupled using an uprod fromhandle 6612 or handle 6632 to cutting block to aid in alignment andstability. In particular, the surface of the distal end of femur is cutparallel to the prepared surface of the tibia with the leg in flexion.The bone cut to the femur yields an imaginary rectangle formed with theparallel surfaces of femur and tibia when the leg is in extension. Itshould be noted that a portion of the femoral condyle is in contact withthe selected spacer block or distractor 6604 with the leg in flexion andthis region is not prepared at this time. In a subsequent step, theremaining surface of the distal end of the femur is prepared. The widthof the gap in extension and in flexion between the cut distal end of thefemur and the prepared tibia surface corresponds to the thickness of thecombined orthopedic implant device comprising the femoral implant, finalinsert, the tibial implant. Ideally, the measured the gap under equalloading in flexion (i.e., the tibia forms a 90 degree angle with thefemur) and extension is similar or equal. The prepared femoral surfacesand the prepared tibial surfaces are parallel throughout the range ofmotion and perpendicular to the mechanical axis of the leg.

Load measurements are made with the leg in flexion and the selectedspacer block or distractor 6604 between the distal end of the femur andthe tibial surface. In a non-limiting example, the measurements asdescribed above should be similar to the measurements made in extension.Adjustments to the load value and the balance between compartments canbe made by soft tissue release or femoral component rotation in flexionwith the selected spacer block or distractor 6604 in place.Alternatively, the femoral implant can be seated on the distal end ofthe femur and measurements taken. Adjustments can be made with thefemoral implant in place. Furthermore, a gap generated by distractor6604 can be adjusted to accommodate differences due to the femoralimplant if required.

The leg with the selected spacer block or distractor 6604 can be takenthrough a complete range of motion. The loading in each compartment canbe monitored on display 6624 and processed by processing unit 6622 overthe range of motion. Processing unit 6622 can compare different pointsin the range of motion to the predetermined load range and thepredetermined differential load range. Should an out-of-range-valuecondition occur, the surgeon can view and note the position of the femurand tibia position on display 6624 and take steps to bring the implantwithin specification. The surgeon can complete the implant surgeryhaving knowledge that both qualitative and quantitative information wasused during the procedure to ensure correct installation. In oneexemplary embodiment, sensors 6606, disposable targets 6610, and lasers6614 are disposed of upon completion of the surgery.

Thus, the sensors will enable the surgeon to measure joint loading whileutilizing soft tissue tensioning to adjust balance and maximizestability of an implanted joint. Similarly, measured data in conjunctionwith positioning can be collected before and during surgery to aid thesurgeon in ensuring that, the implanted device has an equivalentgeometry and range of motion.

Sensors and leads according to the invention can be installed in avariety of ways. One exemplary embodiment employs an ultrasonic cannulasystem 180, which allows external non-radiating visualization of thesensor placement, and is shown in FIG. 67. The cannula 181 houses thetransmitter 182 and the receiver 183. The deployment sensor 184 is,then, optimally positioned for insertion. The ultrasonic arm can, then,be used to obtain a rapid topography of the joint surface and depth. Theultrasonic inserter sends energy waves to the multiple embedded sensors7 that reflect to one another and back to the ultrasonic transducer asshown in FIG. 44. FIG. 44 depicts the ultrasonic sensors 7 usingreflection techniques with the sound wave. The sound waves reflect offthe end of the bone and the embedded sensor 7 back to the receiver inthe ultrasonic inserter. The receiver detects the reflected sound wavesand activates the sensor output to a computer screen for visualizationas shown in FIG. 45.

The ultrasonic wave also exhibits a thru-beam to the tibia. Here, thetransmitter beams the ultrasonic wave to a separate receiver 190. Thefemur/tibia deflect the beam triggering the receiver output. The addedability of the embedded sensors 7 to continually reflect the ultrasonicbeam to the network of sensors 7 allows precise three-dimensionalinformation. The sensor 7 is programmed to compensate for irregularsurfaces and variable surface temperature. The measurement of bone isbased on the processing of the received ultrasound signals. Speed of thesound and the ultrasound velocity both provide measurements on the basisof how rapidly the ultrasound wave propagates through the bone and thesoft tissue. These measures characteristics permit creation of a rapidthree-dimensional geometry, which information can be externally sent tothe computer system that will allow integration of the prosthesis asshown in FIG. 45.

In order for the sensor system to obtain the needed informationregarding the spatial three dimensional topography of the joint, aminimum of three sensors are needed to be implanted into each bone thatis an integral part of the joint. Deployment of the sensor can be by asingle cannula (FIG. 68) with one or several sensors (FIG. 69), or by amultiple sensor deployment cannula (FIG. 70). The sensor has acalibrated trocar that penetrates skin, muscle, ligament, tendon,cartilage and bone. FIG. 71, for example, depicts the deployment of thesensors in an open knee surgery where the soft tissue has been excludedand the cartilage and bone cuts have been made. A handle 190 houses aplunger 191 that controls the depth of sensor deployment. See FIGS. 72to 75. The minimal depth is determined by the amount of cartilage andbone to be cut for the implantation of the prosthesis or implant. Forexample, in the femur and tibia, a minimum of 10 to 15 millimeters iscut. The sensor is deployed deep with respect to that cut so as not tobe dislodged during the procedure and to be able to be used in thepost-operative period. The trocar tip houses the elements of the sensor(FIG. 72) and, upon reaching the desired depth of deployment, the sensor8 is inserted by a release of the locking mechanism (FIG. 46), which,for example, can be a screw, or a rotate-to-unlock joint, a break-away,or any other decoupling mechanism.

Once the sensor system has been inserted, the external energy wave thatwill be used can be ultrasonic or electromagnetic. The use of an opticalarray method could, therefore, be avoided. The deflection of the energythrough the various mediums (cartilage and bone) and the time element ofthe energy wave is received by the sensors 8 and/or reflected back tothe external receiver. By having the various sensors 8, athree-dimensional model is depicted. This enables the surgeon to embedthe sensors (FIG. 71), use them during surgery (FIGS. 45, 49) and, then,leave them implanted to be utilized after surgery (FIGS. 32 and 33).Accordingly, the speed of information transmission is greatly increasedand processed.

FIGS. 50 and 51 depict some elements of the knee joint soft tissue. TheACL, the PCL, the medial collateral ligament, and the lateral collateralligament are important for balancing of a knee joint during surgery. Inone exemplary embodiment, the sensors are embedded into the ligament ofa tendon by a clip mechanism (see FIGS. 52 to 55). The information isreceived and processed by a software system that is integrated into thecomputer-assisted joint surgery device and presents a visual analogue ofan intra-operative joint (FIG. 49). Ligament tension, pressure, shear,etc. is evaluated. A soft-tissue balancing grid aids in the surgeonsapproach regarding soft tissue releases and component rotation.

FIG. 76 depicts a similar sensor system in the hip. The inserter issimilar to a single sensor inserter as shown in FIG. 76 or can bemodified as shown in FIG. 76. The inserter is configured to a cannulatedacetabular reamer that is used in standard hip surgery. The handle 200stabilizes the construct and the sensors 8 are deployed by depressing aplunger in the handle 200. FIG. 78 depicts a cup sensor inserter. Thecannulated holes allow deployment of the sensor 9. The construct can bemodified similar to FIG. 67 to include an ultrasonic component to helpvisualize the anatomy.

FIGS. 72 to 75 depict the development of “smart” inserters and “smart”instruments. The handle 210 of the inserter/instrument houses an arrayof sensors 8 to aid in the precise cutting of the bone (FIG. 74) as wellas the insertion of the prosthesis and sensors (FIGS. 73 and 75). Thesesensors 8 are spatially identified by the ultrasonic/electromagnetictransducer and receiver to allow confirmation that the implant/boneinterface was prepared appropriately and that the implant was insertedto the appropriate depth and angle. The stability of a cemented or pressfit component could, then, be tested. Sensors implanted onto theprosthesis at the time of surgery or prior to surgery also allowprecision insertion and orientation of the prosthesis. Post-operativeimplant evaluation also is performed.

FIG. 77 depicts the insertion of the sensors 8 into a femur. The sensor8 can be deployed from the inside-out, from the outside-in, orincorporated into the distal centralizer of the prosthesis and or thecanal restrictor.

FIG. 79 is an illustration of a system 7900 having sensor arrays inaccordance with an exemplary embodiment. The system disclosed is anon-limiting example used in the installation of an orthopedic devicefor a hip replacement. The appropriate kinematics of the hip joint isachieved by implant alignment and refined by increasing or decreasingthe hips offset or the limb length. One or more sensor arrays 7906 arecoupled to the pelvis 7912 and one or more sensor arrays are placed inthe femur prior to dislocation of the hip. Sensor arrays 7906 provideposition and measurement data on the existing joint that can be comparedlater to the implanted joint or during refinement of the implant toinform the surgeon of the hip joint function. It is noted that the hipjoint sensor integration described here can be utilized in other areasof the skeletal system.

The system comprises one or more tools and implanted orthopedic devicesincorporating sensor arrays in communication with a processing unit7908. The system measures and displays parameters of the hip jointincluding load, position, relational positioning, distance, geometry,and other parameters disclosed hereinabove (e.g., with regard to theknee). In general, the damaged portions of the hip joint are replaced.Typically, the femoral head of the femur is removed and the acetabulumis shaped. The acetabulum is a partial spherical shaped bony region inthe pelvis 7912 that receives the femoral head. It cannot be understatedthat the orthopedic implants have an orientation and geometry similar tothe original bone structure. This can only be achieved if the implantedorthopedic devices can be oriented correctly (hip to pelvis 7912) withsimilar physical geometry and symmetry. Incorrect replacement can leadto hip dislocation, one leg being longer or shorter than the other,instability, and other movement difficulties after implantation.

The acetabulum in the pelvis 7912 is shaped with a reaming tool 7902 ofthe system that removes bony material and cartilage in the region.Reaming tool 7902 includes sensor arrays 7904 that define the varyingdepths and angles in three planes as the acetabulum is shaped. A trialcup is to be inserted that is similar in size to the patient's naturalcup to define the starting angles. Sensor arrays 7906 in the pelvis 7912define the planes of the pelvis 7912. In at least one exemplaryembodiment, sensor arrays 7906 comprise accelerometers. Sensor arrays7904 and 7906 are in communication with a processing unit 7908. As thereamer is installed, sensor arrays 7904 will maintain the visualpositioning the surgeon wants to achieve. This process can be used incutting instruments/reamers during knee, shoulder, ankle, joint, and/orspine surgery. Processing unit 7908 processes information from reamingtool 7902 and displays positional and shape information of the materialremoval process on a screen 7910. Once the acetabulum is shaped, thetrial cup (socket) is selected to be fitted into the shaped acetabulum.

Typically, an interference fit is used to hold the cup in theacetabulum. A cup is selected that is slightly larger than the opening.Glue can also be used to ensure a secure fit if the surgeon deems itnecessary. At this time, the fitting of the cup is difficult because twoangles in relation to the pelvis 7912 must be contemplated in theinsertion process. In at least one exemplary embodiment, an impactioninstrument is fitted with sensors similar to reaming tool 7902 to enablethe surgeon to define cup orientation. For example, accelerometers canbe used to monitor position and relative positioning of the impactioninstrument. In particular, the accelerometers will allow the orientationin at least three planes to achieve appropriate anteversion, opening,and depth.

The impaction instrument fits into a trial cup and includes a handlethat can be rotated to direct a force applied to the end of the handleto a specific region of the cup, thereby positioning the cup in theacetabulum. The sensors of the cup impaction instrument are incommunication with processing unit 7908. The sensors provide positionalinformation of the impaction instrument (and thereby the trial cup) inrelation to the pelvis 7912. Screen 7910 can indicate when the handle ispositioned correctly to drive the cup in at the appropriate angles toseat the acetabular cup fully and define full stability. The surgeon canthen use a mallet to drive in the cup. In a non-limiting example, areamer and an impaction tool can be part of the same tool.

FIG. 80 is an illustration of a hip implant having sensors in accordancewith an exemplary embodiment. A proximal end of a femur 8006 has beenprepared for receiving a femoral implant 8008. The femoral implant 8008includes a femoral head 8010 that is fitted into a trial cup 8012. In atleast one exemplary embodiment, sensor arrays 8004 are in or attached tofemur 8006. The femoral head of the implant can also include sensorarrays. In at least one exemplary embodiment, sensor arrays 8002 areplaced in trial cup 8012. Sensors 7906, 8002, and 8004 are incommunication with processing unit 7908 for providing location anddistance information that is displayed on screen 7910. In particular,the system can make a distance measurement that ensures that femoralimplant 8008 results in an appropriate leg length. More specifically, adistance measured between sensors 7906 and sensors 8004 corresponds to alength measured prior to installing femoral implant 8008. The distanceof installed femoral implant 8008 should be similar to that of the priorspacing. An incorrect distance can result in a different leg length thanthe person had originally, which is very noticeable and is a source ofcomplaint by hip replacement patients. The joint offset can also bemeasured and displayed on screen 7910 using the sensor arrays to displaythe working hip joint in three-dimensional space. The surgeon can makefurther adjustments to prevent rework or potential problems at this timebased on measurements of the actual implanted joint thereby ensuring thebest fit possible.

FIG. 81 is an illustration of a hip implant having load sensors 8002 inaccordance with an exemplary embodiment. System 8100 measuresappropriate implant and implant articulation. In general, femoral head8010 of femoral implant 8008 is made of metal that articulates with apolymer or another metal that forms a bearing surface in the acetabulum.If the alignment of the prostheses is not optimal, the implants canimpinge on each other leading to edge loading, early implant wear, anddislocation.

As mentioned above, trial cup 8012 includes load sensors 8002. Loadsensors 8002 are positioned in different regions of the trial cup andare in communication with processing unit 7908. Once inserted,measurements of the loading in different areas of trial cup 8012 can bemade and displayed on screen 7910. The loading measured by sensors 8002should be within a predetermined range. The cup may not be fully seatedif the measurement is outside the range.

FIG. 82 is an illustration of moving the hip implant to measure load andposition through a range of motion in accordance with an exemplaryembodiment. Sensors 7906, 8002, and 8004 provide position and loadinformation to processing unit 7908. The position of the pelvis and hipin relation to each other can be displayed on screen 7910. Loadmeasurements are taken by sensors 8002 on cup 8012 as the hip is movedover the entire range of motion. The surgeon can use the real-timemeasurements to balance the loading over the range of motion throughligament tensioning and implant positioning. In general, the femoralhead 8010 defines that the cup 8012 is fully seated and that femoralhead 8010 is equally loading the geometry of cup 8012 as the sensorsdefine the position of the joint. This allows the surgeon to rotate theinsert, reposition the cup or femoral implant to achieve optimal implantto implant articulation through all degrees of motion, and define anyaspects of instability or overload.

Fine tuning of the implant can be made utilizing the alignment and loadmeasurements in three dimensions. The impaction instrument can be usedto make fine adjustments in placement of cup 8012 by positioning thehandle and applying a force to move the cup within the acetabulum. Thesurgeon can be directed to apply the force in an appropriate directionby processing unit 7908 to position cup 8012 using an analysis of thedata that is viewed on screen 7910 (e.g., current position versus idealposition). Thus, the system can provide each of alignment, positional,relational positioning, loading, and other measured parameters that aidsthe surgeon in the installation of cup 8012 and femoral implant 8008such that it is fitted very accurately, thereby reducing post-operativecomplications for a patient.

FIG. 83 depicts the lateral view of two spinal segments. The sensorinserter is shown in a percutaneous manner deploying the sensor into thevertebral body. FIG. 84 depicts an axial view of one vertebral level.The sensor 9 is implanted through the pedicle that has been prepared forinstrumentation.

The implanted sensor system following prosthesis insertion is depictedin FIG. 32, an anterior view of the prosthesis, and shows the kneejoint, femoral and tibial prostheses, the polyethylene implant, and theembedded sensors. FIG. 33 depicts a lateral view of the knee joint withthe prosthesis implanted with sensor system. Likewise, FIG. 41 depicts atotal hip prosthesis with the embedded sensor system. FIG. 42 depicts alateral view of the embedded sensors within two segments of thevertebrae and an implant. FIG. 43 depicts a sensor system within avertebral body with a superior (axial) view of a prosthesis/implant.

The sensor system of the present invention can be used pre-operativelyto follow the progression of joint pathology and the different treatmentinterventions. The system can be used intra-operatively to aid in theimplantation of the prosthesis/instrumentation/hardware. In the spine,affects on the neural elements can be evaluated, as well as the vascularchanges during surgery, especially corrective surgery. The sensors can,then, be used post-operatively to evaluate changes over time and dynamicchanges. The sensors are activated intra-operatively and parameterreadings are stored. Immediately post-operatively, the sensor isactivated and a baseline is known.

The sensor system allows evaluation of the host bone and tissueregarding, but not limited to, bone density, fluid viscosity,temperature, strain, pressure, angular deformity, vibration,vascular/venous/lymphatic flow, load, torque, distance, tilt, shape,elasticity, motion, and others. Because the sensors span a joint space,they can detect changes in the implant function. Examples of implantfunctions include bearing wear, subsidence, bone integration, normal andabnormal motion, heat, change in viscosity, particulate matter, andkinematics, to name a few.

The sensors can be powered by internal batteries or by externalmeasures. A patient could be evaluated in bed at night by a non-contactactivation system that can use radio frequency orelectromagnetic/ultrasonic energy. The sensor systems' energy signal canpenetrate the bed, activate the sensors, and transmit to a receiver thatalso can be attached to the bed. The sensors can be “upgraded” over time(e.g., with appropriate software enhancements) to evaluate variousparameters. The sensors can be modified by an external device, such as aflash drive. For example, a set of embedded sensors can monitor theprogression of a spinal fusion that is instrumented. Once a givenparameter is confirmed, the same sensors can be re-programmed to monitorthe adjacent spinal segments to predict increased stress and,ultimately, subluxation of an adjacent level.

Another feature of the sensor system is that it can rotate through aseries of sensor parameters during an evaluation period. An example ofsuch rotation can be evaluation of the bone density as the patientsleeps and, following this, an evaluation of vascular joint fluidviscosity and bearing surfaces. Such evaluation can occur on a fixedtime sequence on specific intervals or randomly as desired. Theinformation can be sent telemetrically to the health care provider bycurrent telephonic devices. Likewise, the patient can be evaluated inthe doctor's office with an external sensor activator. The patientcould, then, go through a series of motions that allow the physician toevaluate implant function, including such parameters as load, torque,motion, stability, etc.

The software system houses the sensor information in a grid that allowsinterval comparisons. The physician, then, evaluates the data, andfunctions that fall outside the standard deviations are highlighted,with these parameters being further evaluated.

FIG. 85 depicts an exemplary diagrammatic representation of a machine inthe form of a computer system 8500 within which a set of instructions,when executed, may cause the machine to perform any one or more of themethodologies discussed above. In some embodiments, the machine operatesas a standalone device. In some embodiments, the machine may beconnected (e.g., using a network) to other machines. In a networkeddeployment, the machine may operate in the capacity of a server or aclient user machine in server-client user network environment, or as apeer machine in a peer-to-peer (or distributed) network environment.

The machine may comprise a server computer, a client user computer, apersonal computer (PC), a tablet PC, a laptop computer, a desktopcomputer, a control system, a network router, switch or bridge, or anymachine capable of executing a set of instructions (sequential orotherwise) that specify actions to be taken by that machine. It will beunderstood that a device of the present disclosure includes broadly anyelectronic device that provides voice, video or data communication.Further, while a single machine is illustrated, the term “machine” shallalso be taken to include any collection of machines that individually orjointly execute a set (or multiple sets) of instructions to perform anyone or more of the methodologies discussed herein.

The computer system 8500 may include a processor 8502 (e.g., a centralprocessing unit (CPU), a graphics processing unit (GPU, or both), a mainmemory 8504 and a static memory 8506, which communicate with each othervia a bus 8508. The computer system 8500 may further include a videodisplay unit 8510 (e.g., a liquid crystal display (LCD), a flat panel, asolid state display, or a cathode ray tube (CRT)). The computer system8500 may include an input device 8512 (e.g., a keyboard), a cursorcontrol device 8514 (e.g., a mouse), a disk drive unit 8516, a signalgeneration device 8518 (e.g., a speaker or remote control) and a networkinterface device 8520.

The disk drive unit 8516 may include a machine-readable medium 8522 onwhich is stored one or more sets of instructions (e.g., software 8524)embodying any one or more of the methodologies or functions describedherein, including those methods illustrated above. The instructions 8524may also reside, completely or at least partially, within the mainmemory 8504, the static memory 8506, and/or within the processor 8502during execution thereof by the computer system 8500. The main memory8504 and the processor 8502 also may constitute machine-readable media.

Dedicated hardware implementations including, but not limited to,application specific integrated circuits, programmable logic arrays andother hardware devices can likewise be constructed to implement themethods described herein. Applications that may include the apparatusand systems of various embodiments broadly include a variety ofelectronic and computer systems. Some embodiments implement functions intwo or more specific interconnected hardware modules or devices withrelated control and data signals communicated between and through themodules, or as portions of an application-specific integrated circuit.Thus, the example system is applicable to software, firmware, andhardware implementations.

In accordance with various embodiments of the present disclosure, themethods described herein are intended for operation as software programsrunning on a computer processor. Furthermore, software implementationscan include, but not limited to, distributed processing orcomponent/object distributed processing, parallel processing, or virtualmachine processing can also be constructed to implement the methodsdescribed herein.

The present disclosure contemplates a machine readable medium containinginstructions 8524, or that which receives and executes instructions 8524from a propagated signal so that a device connected to a networkenvironment 8526 can send or receive voice, video or data, and tocommunicate over the network 8526 using the instructions 8524. Theinstructions 8524 may further be transmitted or received over a network8526 via the network interface device 8520.

While the machine-readable medium 8522 is shown in an example embodimentto be a single medium, the term “machine-readable medium” should betaken to include a single medium or multiple media (e.g., a centralizedor distributed database, and/or associated caches and servers) thatstore the one or more sets of instructions. The term “machine-readablemedium” shall also be taken to include any medium that is capable ofstoring, encoding, or carrying a set of instructions for execution bythe machine and that cause the machine to perform any one or more of themethodologies of the present disclosure.

The term “machine-readable medium” shall accordingly be taken toinclude, but not be limited to: solid-state memories such as a memorycard or other package that houses one or more read-only (non-volatile)memories, random access memories, or other re-writable (volatile)memories; magneto-optical or optical medium such as a disk or tape; andcarrier wave signals such as a signal embodying computer instructions ina transmission medium; and/or a digital file attachment to e-mail orother self-contained information archive or set of archives isconsidered a distribution medium equivalent to a tangible storagemedium. Accordingly, the disclosure is considered to include any one ormore of a machine-readable medium or a distribution medium, as listedherein and including art-recognized equivalents and successor media, inwhich the software implementations herein are stored.

Although the present specification describes components and functionsimplemented in the embodiments with reference to particular standardsand protocols, the disclosure is not limited to such standards andprotocols. Each of the standards for Internet and other packet switchednetwork transmission (e.g., TCP/IP, UDP/IP, HTML, HTTP) representexamples of the state of the art. Such standards are periodicallysuperseded by faster or more efficient equivalents having substantiallythe same functions. Accordingly, replacement standards and protocolshaving the same functions are considered equivalents.

FIG. 86 illustrates a communication network 8600 for measurement andreporting in accordance with an exemplary embodiment. Briefly, thecommunication network 8600 expands broad data connectivity to otherdevices or services. As illustrated, the measurement and reportingsystem 8600 can be communicatively coupled to the communications network8600 and any associated systems or services.

As one example, the measurement system 8655 can share its parameters ofinterest (e.g., angles, load, balance, distance, alignment,displacement, movement, rotation, and acceleration) with remote servicesor providers, for instance, to analyze or report on surgical status oroutcome. This data can be shared for example with a service provider tomonitor progress or with plan administrators for surgical monitoringpurposes or efficacy studies. The communication network 8600 can furtherbe tied to an Electronic Medical Records (EMR) system to implementhealth information technology practices. In other embodiments, thecommunication network 8600 can be communicatively coupled to HISHospital Information System, HIT Hospital Information Technology, HIMHospital Information Management, EHR Electronic Health Record, CPOEComputerized Physician Order Entry, and CDSS Computerized DecisionSupport systems. This provides the ability of different informationtechnology systems and software applications to communicate, to exchangedata accurately, effectively, and consistently, and to use the exchangeddata.

The communications network 8600 can provide wired or wirelessconnectivity over a Local Area Network (LAN) 8601, a Wireless Local AreaNetwork (WLAN) 8605, a Cellular Network 8614, and/or other radiofrequency (RF) system. The LAN 8601 and WLAN 8605 can be communicativelycoupled to the Internet 8620, for example, through a central office. Thecentral office can house common network switching equipment fordistributing telecommunication services. Telecommunication services caninclude traditional POTS (Plain Old Telephone Service) and broadbandservices such as cable, HDTV, DSL, VoIP (Voice over Internet Protocol),IPTV (Internet Protocol Television), Internet services, and so on.

The communication network 8600 can utilize common computing andcommunications technologies to support circuit-switched and/orpacket-switched communications. Each of the standards for Internet 8620and other packet switched network transmission (e.g., TCP/IP, UDP/IP,HTML, HTTP, RTP, MMS, SMS) represent examples of the state of the art.Such standards are periodically superseded by faster or more efficientequivalents having substantially the same functions. Accordingly,replacement standards and protocols having the same functions areconsidered equivalent.

The cellular network 8614 can support voice and data services over anumber of access technologies such as GSM-GPRS, EDGE, CDMA, UMTS, WiMAX,2G, 3G, 4G, WAP, software defined radio (SDR), and other knowntechnologies. The cellular network 8614 can be coupled to base receiver8610 under a frequency-reuse plan for communicating with mobile devices8602.

The base receiver 8610, in turn, can connect the mobile device 8602 tothe Internet 8620 over a packet switched link. The Internet 8620 cansupport application services 8650 and service layers for distributingdata from the measurement system 8655 to the mobile device 8602. Themobile device 8602 can also connect to other communication devicesthrough the Internet 8620 using a wireless communication channel.

The mobile device 8602 can also connect to the Internet 8620 over theWLAN 8605. Wireless Local. Access Networks (WLANs) provide wirelessaccess within a local geographical area. WLANs are typically composed ofa cluster of Access Points (APs) 8604 also known as base stations. Themeasurement system 8655 can communicate with other WLAN stations such aslaptop 8603 within the base station area. In typical WLANimplementations, the physical layer uses a variety of technologies suchas 802.11b or 802.11g WLAN technologies. The physical layer may useinfrared, frequency hopping spread spectrum in the 2.4 GHz Band, directsequence spread spectrum in the 2.4 GHz Band, or other accesstechnologies, for example, in the 5.8 GHz ISM band or higher ISM bands(e.g., 24 GHz, etc).

By way of the communication network 8600, the measurement system 8655can establish connections with a remote server 8630 on the network andwith other mobile devices for exchanging data. The remote server 8630can have access to a database 8640 that is stored locally or remotelyand which can contain application specific data. The remote server 8630can also host application services directly, or over the internet 8620.

It is noted that very little data exists on implanted orthopedicdevices. Most of the data is empirically obtained by analyzingorthopedic devices that have been used in a human subject or simulateduse. Wear patterns, material issues, and failure mechanisms are studied.Although, information can be garnered through this type of study, itdoes yield substantive data about the initial installation,post-operative use, and long-term use from a measurement perspective.Just as each person is different, each device installation is differenthaving variations in initial loading, balance, and alignment. Havingmeasured data and using the data to install an orthopedic device willgreatly increase the consistency of the implant procedure, therebyreducing rework and maximizing the life of the device. In at least oneexemplary embodiment, the measured data can be collected to a databasewhere it can be stored and analyzed. For example, once a relevant sampleof the measured data is collected, it can be used to define optimalinitial measured settings, geometries, and alignments for maximizing thelife and usability of an implanted orthopedic device.

The illustrations of embodiments described herein are intended toprovide a general understanding of the structure of various embodiments,and they are not intended to serve as a complete description of all theelements and features of apparatus and systems that might make use ofthe structures described herein. Many other embodiments will be apparentto those of skill in the art upon reviewing the above description. Otherembodiments may be utilized and derived therefrom, such that structuraland logical substitutions and changes may be made without departing fromthe scope of this disclosure. Figures are also merely representationaland may not be drawn to scale. Certain proportions thereof may beexaggerated, while others may be minimized. Accordingly, thespecification and drawings are to be regarded in an illustrative ratherthan a restrictive sense.

Even though these sensor systems are discussed herein mainly withrespect to the knee, hip, and spine, these systems can be applied to anyof the skeletal systems in the body.

Use of the system has been explained in the description of the presentinvention for a musculoskeletal sensor system. It is to be noted,however, that the present invention is not so limited. The device andmethod according to the invention can be used with any need.

The foregoing description and accompanying drawings illustrate theprinciples, preferred embodiments and modes of operation of theinvention. However, the invention should not be construed as beinglimited to the particular embodiments discussed above. Additionalvariations of the embodiments discussed above will be appreciated bythose skilled in the art.

Therefore, the above-described embodiments should be regarded asillustrative rather than restrictive. Accordingly, it should beappreciated that variations to those embodiments can be made by thoseskilled in the art without departing from the scope of the invention asdefined by the following claims.

1. (canceled)
 2. A tibial implant configured to be positioned at aproximal portion of a tibia and at least partially within the tibia, thetibial implant comprising: a body configured to couple to the tibia; andan electronic components assembly within the body, the electroniccomponents assembly comprising: a sensor configured to monitor at leastone biometric parameter; circuitry for wireless communication; and acontrol circuit.
 3. The tibial implant of claim 2, wherein the sensor isa sensor array comprising a plurality of sensors, wherein the pluralityof sensors are each a different type of sensor.
 4. The tibial implant ofclaim 3, wherein each sensor of the plurality of sensors includes acontrol circuit, communication circuitry, and a power source.
 5. Thetibial implant of claim 3, wherein each sensor of the plurality ofsensors is coupled to a single control circuit for receiving informationfrom each sensor.
 6. The tibial implant of claim 2, wherein the controlcircuit or the circuitry for wireless communication is configuredconvert data received from the senor to a form that can be transmittedby wire or wirelessly.
 7. The tibial implant of claim 2, wherein thecontrol circuit and/or the circuitry for wired or wireless communicationis configured to receive measured data from the sensor and store themeasured data in memory.
 8. The tibial implant of claim 7, wherein thecontrol circuit and/or the circuitry for wired or wireless communicationis configured to periodically send the measured data stored in memory toa processing unit outside of the tibial implant.
 9. The tibial implantof claim 2, wherein the sensor is configured to measure one or morebiometric parameters by command.
 10. The tibial implant of claim 2,wherein the electronic components assembly further comprises a battery,and wherein the sensor is configured to measure motion of the tibialimplant.
 11. The tibial implant of claim 2, wherein the sensor isconfigured to measure relative position of the tibial implant.
 12. Thetibial implant of claim 2, wherein the sensor is configured to measureat least one of: a change in color of synovial fluid over time to detectan infection, pressure applied to the tibial implant, bone density,fluid viscosity, strain, angular deformity, vibration, tilt of thetibial implant, change in viscosity, stability, and vascular flow. 13.The tibial implant of claim 2, wherein the sensor is a plurality ofsensors; and each of the plurality of sensors is a different sensortype.
 14. A tibial sensor assembly configured for positioning within aproximal portion of a tibia, the tibial sensor assembly comprising: asensor configured to measure at least one biometric parameter; anaccelerometer; and a control circuit; wherein the at least one biometricparameter includes at least one of position, acceleration, andvibration.
 15. The tibial sensor assembly of claim 14, wherein thesensor is configured to measure a range of motion of a knee joint. 16.The tibial sensor assembly of claim 14, wherein the sensor is a firstsensor, and further comprising a second sensor configured forpositioning within a femur.
 17. The tibial sensor assembly of claim 15,wherein the control circuit is configured to communicate with aprocessing system outside of the tibia, wherein the processing system isconfigured to display the measured range of motion on an electronicdisplay.
 18. The tibial sensor assembly of claim 14, further comprisinga tibial implant, wherein the sensor, control circuit, and accelerometerare received within the tibial implant.
 19. A tibial implant configuredto be positioned at a proximal portion of a tibia and at least partiallywithin the tibia, the tibial implant comprising: a body assemblyconfigured to couple to the tibia, the body comprising: a tibial trayportion configured to extend over a proximal end of a tibia; a tibialstem portion configured to extend longitudinally through the tibia andextend proximally from a proximal surface of the tibial tray; and anelectronic components assembly positioned within the tibial stem, theelectronics components assembly comprising: a sensor configured tomonitor at least one biometric parameter; and circuitry including apower source and a transmitter.
 20. The tibial implant of claim 19,wherein the electronic components assembly comprises a plurality ofsensors positioned within the tibial stem.
 21. The tibial implant ofclaim 20, wherein at least one of the plurality of sensors positionedwithin the tibial stem is configured to measure motion of the tibialimplant.